Hydrogels in Biology and Medicine: From Molecular Principles to Bionanotechnology

Peppas, Nicholas A.; Hilt, J. Zach; Khademhosseini, Ali; Langer, Robert

doi:10.1002/adma.200501612

Cited by 3,596 publications

(2,863 citation statements)

References 157 publications

(190 reference statements)

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“…1a) with a monoacrylated PEG macromer (PEGA, M n ~ 400 g/mol) in phosphate buffered saline (PBS). Since PEG-based materials are bioinert and present a poorly adhesive substrate for cells, 35 fibronectin (300 nM, R g ~ 14nm 36 ) was included in the macromer solution used for all cell experiments; by this method, the adhesive protein is entrapped within or covalently attached to the hydrogel (mesh size ξ ~ 10nm, as approximated using rubber elasticity and Flory-Rehner theories) and presents integrin-binding adhesive sites. By this approach, cells sense the hydrogel’s adhesive context and geometry, spread on the surface, and form an organized cytoskeleton (Fig.…”

Section: Resultsmentioning

confidence: 99%

Controlled two-photon photodegradation of PEG hydrogels to study and manipulate subcellular interactions on soft materials

et al. 2010

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Cell adhesion and detachment to and from the extracellular matrix (ECM) are critical regulators of cell function and fate due to the exchange of mechanical signals between the cell and its microenvironment. To study this cell mechanobiology, researchers have developed several innovative methods to investigate cell adhesion in vitro; however, most of these culture platforms are unnaturally stiff or static. To better capture the soft, dynamic nature of the ECM, we present a PEG-based hydrogel in which the context and geometry of the extracellular space can be precisely controlled in situ via two-photon induced erosion. Here, we characterize the two-photon erosion process, demonstrate its efficacy in the presence of cells, and subsequently exploit it to induce subcellular detachment from soft hydrogels. A working space was established for a range of laser powers required to induce complete erosion of the gel, and these data are plotted with model predictions. From this working space, two-photon irradiation parameters were selected for complete erosion in the presence of cells. Micron-scale features were eroded on and within a gel to demonstrate the resolution of patterning with these irradiation conditions. Lastly, two-photon irradiation was used to erode the material at the cell-gel interface to remove cell adhesion sites selectively, and cell retraction was monitored to quantify the mesenchymal stem cell (MSC) response to subcellular detachment from soft materials.

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Section: Resultsmentioning

confidence: 99%

Controlled two-photon photodegradation of PEG hydrogels to study and manipulate subcellular interactions on soft materials

et al. 2010

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“…Great attention has been 33 focused Q4 on hydrogels as biopolymers because of its resemblance to 34 the extracellular fluids (Fisher et al, 2014;Malda et al, 2013). They 35 have been studied for different medical applications, such as drug 36 delivery systems and bionanotechnology (Ankareddi and Brazel,37 2007; Gaharwar et al, 2014;Peppas et al, 2006). In particular, the 38 natural polysaccharide agarose, which is a thermo sensitive 39 hydrogel, has been successfully used in tissue engineering and 40 other biological applications (Cheng et al, 2007;Gruber et al, 41 2006; Luo and Shoichet, 2004;Marras-Marquez et al, 2014;Rotter 42 et al, 1998).…”

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confidence: 99%

Tuning dual-drug release from composite scaffolds for bone regeneration

Paris

Román

Manzano

et al. 2015

International Journal of Pharmaceutics

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Keywords:Dual-drug delivery system Designed porous scaffold Ibuprofen Zoledronic acid Co-delivery release Tissue engineering A B S T R A C TThis work presents the tuning of drug-loaded scaffolds for bone regeneration as dual-drug delivery systems. Two therapeutic substances, zoledronic acid (anti-osteoporotic drug) and ibuprofen (antiinflammatory drug) were successfully incorporated in a controlled manner into three dimensional designed porous scaffolds of apatite/agarose composite. A high-performance liquid chromatography method was optimized to separate and simultaneously quantify the two drugs released from the dualdrug codelivery system. The multifunctional porous scaffolds fabricated show a very rapid delivery of anti-inflammatory (interesting to reduce inflammation after implantation), whereas the antiosteoporotic drug showed sustained release behaviour (important to promote bone regeneration). Since ibuprofen release was faster than desired, this drug was encapsulated in chitosan spheres which were then incorporated into the scaffolds, obtaining a release profile suitable for clinical application. The results obtained open the possibility to simultaneously incorporate two or more drugs to an osseous implant in a controlled way improving it for bone healing application.2015 Published by Elsevier B.V. 7

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“…[6] Programing specific mechanical and biochemical behaviors within hydrogels is simply a question of regulating the design of the polymer backbone and the mode of synthesis. [20] In this section, we will discuss bioinspired approaches to engineering environmental adaptation in synthetic materials, with a focus on forward design of biomimetic behaviors in smart hydrogels.…”

Section: Bioinspired Environmental Feedback and Adaptationmentioning

confidence: 99%

Biomimicry, Biofabrication, and Biohybrid Systems: The Emergence and Evolution of Biological Design

Raman

Bashir

2017

Adv Healthcare Materials

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how the concept of bioinspiration, or imitating biological design and functionality in synthetic materials, created a new class of "smart" biomimetic materials. Then, we shall discuss how the continuing development of enabling manufacturing technologies, such as 3D printing and microfluidics, has established the separate subdiscipline of biofabrication for tissue engineering, or "building with biology." Finally, we shall investigate the convergence of these two fields into the emerging discipline of biohybrid design, the use of biological materials to power non-natural functional behaviors in synthetic machines. Throughout this report, we will revisit a single class of materials, hydrogels, as a case study of biological design in the context of each subfield, and discuss how the constraints, underlying principles, and end-use applications differ in each case. We will also discuss ethical considerations of biological design, with a special focus on forward engineering non-natural or hypernatural functional behaviors in biohybrid systems. We will conclude with recommendations for implementing biological design into educational curricula, ensuring effective and responsible practices for the next generation of engineers and scientists. Biomimicry and Bioinspired DesignA deeper understanding of the underlying design principles that govern biological systems has inspired the field of biomimicry. [1,2] Observing adaptive phenomena in nature, scientists and engineers have sought to extract the components of biological design responsible for this behavior and replicate the behavior in synthetic materials. Fundamentally, this involves understanding the building blocks or base units from which a biological material is built, the hierarchical assembly of these building blocks, and the interactions and interfaces between them.In this section, we will discuss strategies that engineers and scientists have employed to engineer bioinspired hierarchy, from bottom-up self-assembly and top-down engineered assembly. We will present several key demonstrations of stimulus-responsive hydrogels ranging from the micro-to the macroscale, and investigate novel demonstrations in biomimetic actuation and movement. We will conclude with the remaining challenges in the field of biomimicry and discuss the potential future impact of bioinspired design.The discipline of biological design has a relatively short history, but has undergone very rapid expansion and development over that time. This Progress Report outlines the evolution of this field from biomimicry to biofabrication to biohybrid systems' design, showcasing how each subfield incorporates bioinspired dynamic adaptation into engineered systems. Ethical implications of biological design are discussed, with an emphasis on establishing responsible practices for engineering non-natural or hypernatural functional behaviors in biohybrid systems. This report concludes with recommendations for implementing biological design into educational curricula, ensuring effective and responsible practice...

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Hydrogels in Biology and Medicine: From Molecular Principles to Bionanotechnology

Cited by 3,596 publications

References 157 publications

Controlled two-photon photodegradation of PEG hydrogels to study and manipulate subcellular interactions on soft materials

Controlled two-photon photodegradation of PEG hydrogels to study and manipulate subcellular interactions on soft materials

Tuning dual-drug release from composite scaffolds for bone regeneration

Biomimicry, Biofabrication, and Biohybrid Systems: The Emergence and Evolution of Biological Design

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