Relating material surface heterogeneity to protein adsorption: the effect of annealing of micro-contact-printed OTS patterns

Hodgkinson, Gerald N.; Hlady, Vladimir

doi:10.1163/1568561054352612

Cited by 7 publications

(7 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is possible this is due to a difference in adsorption of Lam95 onto the PDMS stamp used for microcontact printing, which has been reported in other systems. 37 Or is it due to a difference in transfer of Lam95 from the PDMS stamp to the PIPAAm surface. However, additional studies will be required to determine if either of these occur, and if so why.…”

Section: Resultsmentioning

confidence: 99%

Spontaneous helical structure formation in laminin nanofibers

Szymanski

Feinberg

2015

J. Mater. Chem. B

View full text Add to dashboard Cite

Laminin is a cross-shaped heterotrimer composed of three polypeptides chains that assembles into an insoluble extracellular matrix (ECM) network as part of the basement membrane, serving a vital role in many processes such as embryonic development, differentiation, and muscle and nerve regeneration. Here we engineered monodisperse laminin nanofibers using a surface-initiated assembly technique in order to investigate how changes in protein composition affect formation and structure of the network. Specifically, we compared laminin 111 with varying degrees of purity and with and without entactin to determine whether these changes alter biophysical properties. All the laminin types were reproducibly patterned as 200 μm long, 20 μm wide nanofibers that were successfuly released during surface-initiated assembly into solution. All nanofibers contracted upon release, and while initial lengths were identical, lengths of released fibers depended on the laminin type. Uniquely, the laminin 111 at high purity (>95%) and without entactin spontaneouly formed helical nanofibers at greater than 90%. Atomic force microscopy revealed that the nanofiber contraction was associated with a change in nanostructure from fibrillar to nodular, suggestive of refolding of laminin molecules into a globular-like conformation. Further, for the high purity laminin that formed helices, the density of the laminin at the edges of the nanofiber was higher than in the middle, providing a possible origin for the differential pre-stress driving the helix formation. Together, these results show that variation in the purity of laminin 111 and presence of entactin can have significant impact on the biophysical properties of the assembled protein networks. This highlights the fact that our understanding of protein assembly and function is still incomplete and that cell-free, in vitro assays can provide unique insights into the ECM.

show abstract

Section: Resultsmentioning

confidence: 99%

Spontaneous helical structure formation in laminin nanofibers

Szymanski

Feinberg

2015

J. Mater. Chem. B

View full text Add to dashboard Cite

show abstract

“…A fluorescence microscopy imaging technique described in previous work [26] was utilized to determine the surface density of protein layer or clusters. Laminin densities were determined from three separate samples imaged at 8 to 10 locations each.…”

Section: Methodsmentioning

confidence: 99%

The role of well-defined patterned substrata on the regeneration of DRG neuron pathfinding and integrin expression dynamics using chondroitin sulfate proteoglycans

2012

Self Cite

View full text Add to dashboard Cite

Injured neurons intrinsically adapt to and partially overcome inhibitory proteoglycan expression in the central nervous system by upregulating integrin expression. It remains unclear however, to what extent varying proteoglycan concentrations influence the strength of this response, how rapidly neurons adapt to proteoglycans, and how pathfinding dynamics are altered over time as integrin expression is modulated in response to proteglycan signals. To investigate these quandaries, we created well-defined substrata in which postnatal DRG neuron pathfinding dynamics and growth cone integrin expression were interrogated as a function of proteoglycan substrata density. DRGs responded by upregulating integrin expression in a proteoglycan dose dependent fashion and exhibited robust outgrowth over all proteoglycan densities at initial time frames. However, after prolonged proteoglycan exposure, neurons exhibited decreasing velocities associated with increasing proteoglycan densities, while neurons growing on low proteoglycan levels exhibited robust outgrowth at all time points. Additionally, DRG outgrowth over proteoglycan density step boundaries, and a brief β1 integrin functional block proved that regeneration was integrin dependent and that DRGs exhibit delayed slowing and loss in persistence after even transient encounters with dense proteoglycan boundaries. These findings demonstrate the complexity of proteoglycan regulation on integrin expression and regenerative pathfinding.

show abstract

“…A fluorescence microscopy imaging technique described in previous work [20] was utilized to determine absolute protein film densities for the various patterns produced. Briefly, a Nikon Eclipse E600 Microscope (Melville, NY) equipped with a Nikon Plan Fluor 100x, 1.30 N.A.…”

Section: Protein Pattern Characterizationmentioning

confidence: 99%

“…Ultrasharp tip triangular cantilevers (MikroMasch, Wilsonville, OR) used to probe the various protein layers were chemically modified with hydrophobic organosilane chains in a previously described procedure [20] prior to taking measurements.…”

Section: Protein Pattern Characterizationmentioning

confidence: 99%

The differential influence of colocalized and segregated dual protein signals on neurite outgrowth on surfaces

2007

Self Cite

View full text Add to dashboard Cite

We present an in vitro micropatterning approach in which the density and spatial presentation of two separate protein layers can be independently controlled to form cell stripe assays through (1) the simultaneous application of microcontact printing (μCP) and microfluidic network patterning (μFN) to generate alternating stripes of pure single protein layers or (2) through μCP onto a pre-adsorbed homogeneous protein layer to generate alternating single and dual protein stripes. This approach enabled the creation of choice boundaries in which protein-protein interactions were limited and the effects of spatially segregated or colocalized dual protein signals on model primary neuronal behavior could be readily interrogated and compared on both glass and tissue culture polystyrene substrates. Dorsal root ganglion (DRG) cell body attachment was dictated largely by non-specific cell adhesion interactions and interactions between the guidance molecules laminin and aggrecan were insufficient to explain aggrecan inhibition on neurite outgrowth. The presentation of a specific laminin epitope stabilized by interactions with aggrecan and destabilized by μCP was a strong predictor of neurite promoting activity. These observations provide evidence that aggrecan is intrinsically inhibitory and that laminin-aggrecan interactions do not diminish laminin growth promoting properties.

show abstract

Relating material surface heterogeneity to protein adsorption: the effect of annealing of micro-contact-printed OTS patterns

Cited by 7 publications

References 44 publications

Spontaneous helical structure formation in laminin nanofibers

Spontaneous helical structure formation in laminin nanofibers

The role of well-defined patterned substrata on the regeneration of DRG neuron pathfinding and integrin expression dynamics using chondroitin sulfate proteoglycans

The differential influence of colocalized and segregated dual protein signals on neurite outgrowth on surfaces

Contact Info

Product

Resources

About