Click hydrogels, microgels and nanogels: Emerging platforms for drug delivery and tissue engineering

Jiang, Yanjiao; Chen, Jing; Deng, Chao; Suuronen, Erik J.; Zhong, Zhiyuan

doi:10.1016/j.biomaterials.2014.03.001

Cited by 635 publications

(444 citation statements)

References 164 publications

Supporting

Mentioning

440

Contrasting

Unclassified

Order By: Relevance

“…49,50 Conversely, the cells remained rounded and underwent apoptosis in our negative control hydrogel fabricated from synthetic polymers. Synthetic polymers lack the focal adhesion points to anchor the cells that resulted in early apoptosis to cells.…”

Section: Versatility Of Hydrogels As Substrate and For 3-d Cell Encapmentioning

confidence: 99%

Functionalised type-I collagen as a hydrogel building block for bio-orthogonal tissue engineering applications

et al. 2016

View full text Add to dashboard Cite

In this study, we derivatized type I collagen without altering its triple helical conformation to allow for facile hydrogel formation via Micheal addition of thiols to methacrylates without the addition of other crosslinking agents. This method provides the flexibility needed for fabrication of injectable hydrogels or pre-fabricated implantable scaffolds, using the same components by tuning the modulus from Pa to kPa. Enzymatic degradability of the hydrogels can be also easily fine tuned by variation of the ratio and type of cross-linking component. The structural morphology reveals lamellar structure mimicking native collagen fibrils. The versatility of this material is demonstrated by its use as a pre-fabricated substrate for culturing human corneal epithelial cells, and as an injectable hydrogel for 3-D encapsulation of cardiac progenitor cells.Keywords: bio-orthogonal chemistry, tissue engineering, pre-fabricated scaffolds, injectable scaffolds, cell compatible. IntroductionThe extracellular matrix (ECM) provides mechanical support as well as instructive signals for cell development, migration, proliferation, survival and function. Natural biopolymers derived from the ECM are therefore by nature, very biocompatible and bio-interactive. [1][2][3] The most abundant is collagen that has extensively been used to prepare scaffolds for tissue repair and engineering. This structural ECM component has, however limited number of functional groups that can be used for direct crosslinking. 4, 5 The main functional groups are amine and carboxylic acids, which allows collagen to crosslinked (e.g. via UV, thermal heating, carbodiimides, epoxy or aldehyde crosslinkers). Conversely, synthetic polymers such as poly (ethylene) glycols, poly (lactic acids), poly (methacryl/acryl amides) etc.), are easily chemically modified for facile processing than collagen.6 However, synthetic polymers have issues with biocompatibility, degradability and do not completely integrate within the host.7-9 Hence, synthetic routes to introduce biocompatible crosslinkable modifications on the protein structure, (reactive moieties), are highly desirable for the development of the next generation of regenerative materials for tissue engineering. Particularly, introducing reactive moieties in collagen would expand its functionality allowing for development of a wider range of scaffolds that can serve as regeneration templates. 10, 11 Several routes to render collagen more processable while retaining its in vitro/ in vivo or clinical bio interactive capacity for promoting tissue regeneration have been explored. [12][13][14] The simplest method is blending collagen with natural or synthetic polymers (such as hyaluronic acid, chitosan, poly(ethylene oxide), polylactic acid, and polyglycolic acid) to fabricate scaffolds. 5, 15 Crosslinked collagen-chitosan hydrogels, which were mechanically stronger than collagen alone, promoted angiogenesis and has been used for islet transplantations in murine models. 16 Li et al.co-polymerized collagen with lam...

show abstract

Section: Versatility Of Hydrogels As Substrate and For 3-d Cell Encapmentioning

confidence: 99%

Functionalised type-I collagen as a hydrogel building block for bio-orthogonal tissue engineering applications

et al. 2016

View full text Add to dashboard Cite

show abstract

“…These soft colloids can absorb a large amount of water, where the extent of swelling often depends on environmental conditions, such as temperature and/or pH; this stimulus responsiveness makes microgels excellent candidates for biotechnological applications, such as biomaterials and drug delivery [1][2][3][4][5][6]. Evidently, the uptake of small charged drugs by microgels is strongly conditioned by electrostatic forces.…”

Section: Introductionmentioning

confidence: 99%

Impact of volume transition on the net charge of poly-N-isopropyl acrylamide microgels

et al. 2016

View full text Add to dashboard Cite

We explore the electrostatic properties of poly-N-isopropyl acrylamide microgels in dilute, quasi-de-ionized dispersions and show that the apparent net charge of these thermosensitive microgels is an increasing function of their size, the size being conveniently varied by temperature. Our experimental results obtained in a combination of light scattering, conductivity, and mobility experiments are consistent with those obtained in Poisson-Boltzmann cell model calculations, effectively indicating that upon shrinking the number of counterions entrapped within the microgels increases. Remarkably, this behavior shows that the electrostatic energy per particle remains constant upon swelling or deswelling the microgel, resulting in a square root dependence of the net charge on the particle radius.

show abstract

“…T ECHNIQUES that could precisely pattern hydrogels with tunable geometric shape and size in micro/nano scale are desired for developing hydrogels' applications in drug delivery [1], cell encapsulation [2], [3], cell-environment interaction research [4], [5] and tissue engineering [6]- [8]. To date, three-dimensional micro hydrogel structures have been created by a variety of methods, including photolithography, softlithography (e.g., micro-contact printing, microfluidic patterning, and micro molding) [9]- [11].…”

Section: Introductionmentioning

confidence: 99%

3-D Non-UV Digital Printing of Hydrogel Microstructures by Optically Controlled Digital Electropolymerization

Liu

Pan

Liu

et al. 2015

J. Microelectromech. Syst.

View full text Add to dashboard Cite

Abstract-A technique using digital masks without ultraviolet light to rapidly print 3-D biopolymer structures with complex microarchitectures in a microfluidic chip has been demonstrated. In this approach, a customized system is used to project light images on a photoconductive substrate in order to create localized virtual electrodes when an alternating electric field is applied across the fluidic medium in an optically controlled digital electropolymerization chip. Upon these virtual electrodes, the localized electric fields are generated, which could activate the polymerization of acrylate-based molecules, such as poly(ethylene glycol) diacrylate (PEGDA), to form microstructures with the same shapes as the projected light images. We have demonstrated that the 3-D PEGDA microstructures with the customized shapes could be fabricated rapidly through a layer-by-layer process by applying a series of digital masks (projected light images). With our current projection and microscopy system, the fabrication of microhydrogel structures with a lateral resolution of 3 µm and an adjustable thickness ranging from tens of nanometers to hundreds of micrometers has been demonstrated. In summary, this novel technique provides an efficient process for the rapid printing of the 3-D biopolymer-based microstructures, and could enable many future applications in a mechanoanalysis of cancer cells, tissue engineering, and drug screening.[2015-0110]

show abstract

Click hydrogels, microgels and nanogels: Emerging platforms for drug delivery and tissue engineering

Cited by 635 publications

References 164 publications

Functionalised type-I collagen as a hydrogel building block for bio-orthogonal tissue engineering applications

Functionalised type-I collagen as a hydrogel building block for bio-orthogonal tissue engineering applications

Impact of volume transition on the net charge of poly-N-isopropyl acrylamide microgels

3-D Non-UV Digital Printing of Hydrogel Microstructures by Optically Controlled Digital Electropolymerization

Contact Info

Product

Resources

About