Development of A 3d Cryoprinter For Printing Soft Biomaterials

As a novel class of biomaterials, nucleopeptides, via the conjugation of nucleobases and peptides, usually self-assemble to form nanofibres driven mainly by hydrogen bonds. Containing nucleobase(s), nucleopeptides have a unique property—interacting with nucleic acids. Here we report the design and characterization of nucleopeptides that self-assemble in water and are able to interact with single-stranded DNAs (ssDNAs). Containing nucleobases on their side chains, these nucleopeptides bind with the ssDNAs, and the ssDNAs reciprocally affect the self-assembly of nucleopeptides. In addition, the interactions between nucleopeptides and ssDNAs also decrease their proteolytic resistance against proteinase K, which further demonstrates the binding with ssDNAs. The nucleopeptides also interact with plasmid DNA and deliver hairpin DNA into cells. This work illustrates a new and rational approach to create soft biomaterials by the integration of nucleobases and peptides to bind with DNA, which may lead to the development of nucleopeptides for controlling DNA in cells.

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Progress in material design for biomedical applications

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1516247112 ◽

2015 ◽

Vol 112 (47) ◽

pp. 14444-14451 ◽

Cited By ~ 140

Author(s):

Mark W. Tibbitt ◽

Christopher B. Rodell ◽

Jason A. Burdick ◽

Kristi S. Anseth

Keyword(s):

Biomedical Applications ◽

Material Design ◽

The Body ◽

Biological Complexity ◽

Recent Developments ◽

Primary Focus ◽

Controlled Structure ◽

High Level ◽

Soft Biomaterials ◽

Organ Replacement

Biomaterials that interface with biological systems are used to deliver drugs safely and efficiently; to prevent, detect, and treat disease; to assist the body as it heals; and to engineer functional tissues outside of the body for organ replacement. The field has evolved beyond selecting materials that were originally designed for other applications with a primary focus on properties that enabled restoration of function and mitigation of acute pathology. Biomaterials are now designed rationally with controlled structure and dynamic functionality to integrate with biological complexity and perform tailored, high-level functions in the body. The transition has been from permissive to promoting biomaterials that are no longer bioinert but bioactive. This perspective surveys recent developments in the field of polymeric and soft biomaterials with a specific emphasis on advances in nano- to macroscale control, static to dynamic functionality, and biocomplex materials.

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A Modular Test Platform for Micromechanical Tensile Testing of Soft Biomaterials

Volume 3: Biomedical and Biotechnology Engineering ◽

10.1115/imece2018-87259 ◽

2018 ◽

Cited By ~ 1

Author(s):

Wilson Eng ◽

Max Kim ◽

Anand Ramasubramanian ◽

Sang-Joon John Lee

Keyword(s):

Force Measurement ◽

Low Noise ◽

Particle Tracing ◽

Viscoelastic Parameters ◽

Tensile Tester ◽

Low Profile ◽

Blood Clots ◽

Microscope Imaging ◽

Using Data ◽

Soft Biomaterials

Mechanical properties of biomaterials are difficult to characterize experimentally because many relevant biomaterials such as hydrogels are very pliable and viscoelastic. Furthermore, test specimens such as blood clots retrieved from patients tend to be small in size, requiring fine positioning and sensitive force measurement. Mechanobiological studies require fast data recording, preferably under simultaneous microscope imaging, in order to monitor events such as structural remodeling or localized rupture while strain is being applied. A low-profile tensile tester that applies prescribed displacement up to several millimeters and measures forces with resolution on the order of micronewtons has been designed and tested, using alginate as a representative soft biomaterial. 1.5% alginate (cross-linked with 0.1 M and 0.2 M calcium chloride) has been chosen as a reference material because of its extensive use in tissue engineering and other biomedical applications. Prescribed displacement control with rates between 20 μm/s and 60 μm/s were applied using a commercial low-noise nanopositioner. Force data were recorded using data acquisition and signal conditioning hardware with sampling rates as high as 1 kHz. Elongation up to approximately 10 mm and force in the range of 250 mN were measured. The data were used to extract elastic and viscoelastic parameters for alginate specimens. Another biomaterial, 2% agarose, was also tested to show versatility of the apparatus for slightly stiffer materials. The apparatus is modular such that different load cells ranging in capacity from hundreds of millinewtons to tens of newtons can be used. The apparatus furthermore is compatible with real-time microscope imaging, particle tracing, and programmable positioning sequences.

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