Name: dendrimer-based uneven nanopatterns to locally control surface adhesiveness: a method to direct chondrogenic differentiation
Uploaded: 2018-01-20T14:00:00
Description: Watch this Scientific Journal Video about Dendrimer-based Uneven Nanopatterns to Locally Control Surface Adhesiveness: A Method to Direct Chondrogenic Differentiation at JoVE.com

The authors acknowledge Oriol Font-Bach and Albert G. Casta&#241;o for their help in dmin quantification. They also acknowledge the Advanced Digital Microscopy Unit at the Institute for Research in Biomedicine (IRB Barcelona) to let the authors record the video in their premises. This work was supported by the Networking Biomedical Research Center (CIBER), Spain. CIBER is an initiative funded by the VI National R&amp;D&amp;i Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program, CIBER Actions, and the Instituto de Salud Carlos III, with the support of the European Regional Development Fund. This work has been supported by the Commission for Universities and Research of the Department of Innovation, Universities, and Enterprise of the Generalitat de Catalunya (2014 SGR 1442). It was also funded by the projects OLIGOCODES (No. MAT2012-38573-C02) and CTQ2013-41339-P, awarded by the Spanish Ministry of Economy and Competitiveness, in addition to INTERREG V-A Spain-Portugal 2014-2020 POCTEP (0245_IBEROS_1_E). C.R.P. acknowledges financial support from the Spanish Ministry of Economy and Competitiveness grant (No. IFI15/00151).

1. Substrate Preparation
<ol>
	<li>Annealing 1.4 x 1.1 cm Au(111) on Mica Substrates.
	<ol>
		<li>Place the Au(111) substrate on a glass-ceramic hob and anneal it with a butane flame for 3 min. Allow the substrate to cool under an argon atmosphere. Repeat this step for each Au(111) substrate. 
		NOTE: Au(111) substrates should be used immediately after annealing.</li>
	</ol>
	</li>
	<li>Preparation of Poly(L-Lactic Acid) (PLLA)-Coated Glass Substrates.
	<ol>
		<li>Cut and wash the...

<ol>
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During the development of the described protocol, a number of critical steps should be considered. The first refers to nanopattern characterization with scanning probe microscopy techniques. To visualize the nanopatterns, the surface where patterning is produced must have a roughness value below the mean diameter of the dendrimers, which is around 4&#8211;5 nm as measured by STM (Figure 1B). Also, it should be taken into account that high resolution STM imaging is restricted to conductive substrates, in ...

Here we describe a simple and versatile dendrimer-based nanopatterning procedure to obtain cell culture surfaces that allow the control of local adhesiveness at the nanoscale. Nanoscale details of ECM organization have been reported,1,2,3 and the nanopatterning of cell adhesion surfaces has provided deep insights into the cellular requirements related to adhesion4,5. Experiments using micellar lithography-based nanopatterns revealed a threshold value of around 70 nm for RGD peptide nanospacing, cell adhesion being significantly delayed above this value6,7,8,9. These studies also highlighted the greater influence of local than global ligand density on cell adhesion9,10,11.
During morphogenesis, cell interactions with the surrounding environment trigger the first differentiation events, which continue until final complex tissue structures have been formed. Within this framework, nanopatterned surfaces have been used to tackle the influence of the initial cell-surface interactions on morphogenesis. Lithography-based RGD nanopatterns with a lateral spacing of 68 nm in &#946;-type Ti-40Nb alloys help to maintain the undifferentiated phenotype of non-committed stem cells12, while RGD nanospacings of between 95 and 150 nm enhance the differentiation of mesenchymal stem cells (MSCs) towards adipogenic/osteogenic13,14,15 and chondrogenic fates16. Also, self-assembling macromolecules modified with signaling components have been shown to direct cell adhesion and differentiation by providing nanoscale architectural regulation of the signaling cues17. In this regard, the deposition of dendrimers with cell-interacting moieties in their outer sphere18,19,20 onto surfaces has been used to study cell adhesion21,22, morphology23,24, and migration events25,26. Nevertheless, the lack of surface characterization in these studies makes it difficult to establish any correlation between dendrimer surface configuration and cell response.
Dendrimer nanopatterns with liquid-like order and defined spacing can be obtained when dendrimers adsorb to low-charged surfaces from solutions with low ionic strengths.27 On the basis of this property, here we present a method to obtain large-scale uneven nanopatterns of RGD-functionalized dendrimers on low-charged surfaces that permit the nanoscale control of local RGD surface density. Water contact angle (CA), X-ray photoelectron spectroscopy (XPS) and scanning probe microscopy techniques (STM and AFM nanopatterns) show that local ligand densities can be adjusted modifying the initial dendrimer concentration in solution. The local RGD surface density is quantified from AFM images by probability contour maps of minimum interparticle distances and then correlated with cell experiments. Compared with other nanopatterning techniques4, dendrimer-based nanopatterning is straightforward and can be easily scaled up to large surface areas, thus being fully compatible with cell culture applications. Nanopatterns are used as bioactive substrates to evaluate the effect of the local RGD surface density on cell adhesion28 and on the chondrogenic induction of adult human MSCs29. Our results show that RGD dendrimer-based nanopatterns sustain cell growth and that cell adhesion is reinforced by high local RGD surface densities. In the differentiation experiments, intermediate adhesiveness of cells to the substrates favored MSC condensation and early chondrogenic differentiation. Due to the ease with which dendrimer peripheral groups can be modified, the method described here can be further extended to other ECM ligands that exert concentration-dependent effects on cells.

<table border="0" cellpadding="0" cellspacing="0" width="1384">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">Gold (111) on mica. 1.4x1.1 cm&#160;</td>
			<td style="width:169px;">Spi Supplies</td>
			<td style="width:307px;">466PS-AB</td>
			<td style="width:405px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">Glass micro slides, plain</td>
			<td style="width:169px;">Corning</td>
			<td style="width:307px;">2947-75x25</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">Deionized water</td>
			<td style="width:169px;">Millipore</td>
			<td style="width:307px;"></td>
			<td>18M&#937; cm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">Ethanol 96%</td>
			<td style="width:169px;">PanReac</td>
			<td style="width:307px;">131085.1212</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:504px;">L-Lactide/DL-Lactide copolymer</td>
			<td style="width:169px;">Corbion</td>
			<td style="width:307px;"></td>
			<td>95/05 molar ratio</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:504px;">1,4 - dioxane</td>
			<td style="width:169px;">Sigma-Aldrich</td>
			<td style="width:307px;">296309-1L</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:504px;">Silicone oil, high temperature</td>
			<td style="width:169px;">Acros Organics</td>
			<td style="width:307px;">174665000</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:504px;">Spinner</td>
			<td style="width:169px;">Laurell</td>
			<td style="width:307px;">WS-650MZ-23NPP/Lite</td>
			<td></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;width:504px;">Tissue culture laminar flow hood</td>
			<td style="width:169px;">Telstar</td>
			<td style="width:307px;">Bio II Advance</td>
			<td>Class II biological safety cabinet</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">Filter unit</td>
			<td style="width:169px;">Millex-GP</td>
			<td style="width:307px;">SLGP033RB</td>
			<td>0.22 &#181;m</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">Syringe 10 mL</td>
			<td style="width:169px;">Discardit</td>
			<td style="width:307px;">309110</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">Atomic Force microscope</td>
			<td style="width:169px;">Veeco Instruments</td>
			<td style="width:307px;">Dimension 3000 AFM instrument</td>
			<td></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;width:504px;">Silicon AFM probes</td>
			<td style="width:169px;">Budget Sensors</td>
			<td style="width:307px;">Tap300AI-G</td>
			<td>Resonant Freq. 300 kHz, k = 40 N/m</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:504px;">Scanning tunneling microscope</td>
			<td style="width:169px;">Molecular Imaging</td>
			<td style="width:307px;">PicoSPM microscope</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:504px;">Pt0.8:Ir0.2 wire</td>
			<td style="width:169px;">Advent</td>
			<td style="width:307px;">PT671012</td>
			<td>Diameter 0.25 mm</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:504px;">WSxM 4.0 software</td>
			<td style="width:169px;">Nanotec electronica</td>
			<td style="width:307px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">Optical contact angle (CA) system</td>
			<td style="width:169px;">Dataphysics</td>
			<td style="width:307px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">SCA20 software</td>
			<td style="width:169px;">Dataphysics</td>
			<td style="width:307px;"></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:504px;">X-ray photoelectron spectrometer</td>
			<td style="width:169px;">Physical Electronics</td>
			<td style="width:307px;">Perkin-Elmer PHI 5500 Multitechnique System</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">Fibronectin from bovine plasma</td>
			<td style="width:169px;">Sigma-Aldrich</td>
			<td style="width:307px;">F1141-1MG</td>
			<td>1.0 mL solution</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">Dulbecco&#39;s Phosphate Buffer Saline (DPBS)</td>
			<td style="width:169px;">Gibco</td>
			<td style="width:307px;">21600-10</td>
			<td>Powder</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">Mouse embryo fibroblasts</td>
			<td style="width:169px;">ATCC</td>
			<td style="width:307px;">ATCC CRL-1658</td>
			<td>NIH/3T3</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:504px;">Dulbecco&#39;s modified eagle medium (DMEM) liquid high glucose</td>
			<td style="width:169px;">Gibco</td>
			<td style="width:307px;">11960044</td>
			<td>liquid high glucose, no glutamine, 500 mL</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">Fetal Bovine Serum (FBS)</td>
			<td style="width:169px;">Gibco</td>
			<td style="width:307px;">16000044</td>
			<td>500 mL</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">L-Glutamine</td>
			<td style="width:169px;">Invitrogen</td>
			<td style="width:307px;">25030</td>
			<td>200 mM (100X)</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;width:504px;">Penicillin-streptomycin</td>
			<td style="width:169px;">Invitrogen</td>
			<td style="width:307px;">15140</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:504px;">Sodium pyruvate</td>
			<td style="width:169px;">Invitrogen</td>
			<td style="width:307px;">11360039</td>
			<td>100 mL</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">T75 culture flasks</td>
			<td style="width:169px;">Nunclon</td>
			<td style="width:307px;">156499</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:504px;">Trypsin</td>
			<td style="width:169px;">Life Technologies</td>
			<td style="width:307px;">25200072</td>
			<td>0,25% EDTA</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">Centrifuge</td>
			<td style="width:169px;">Hermle Labortechnik</td>
			<td style="width:307px;">Z 206 A</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:504px;">Non-tissue culture treated plate, 12 well</td>
			<td style="width:169px;">Falcon</td>
			<td style="width:307px;">351143</td>
			<td>Non-adherent</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">Adipose-derived hMSCs</td>
			<td style="width:169px;">ATCC</td>
			<td style="width:307px;">ATCC PCS-500-011</td>
			<td>Cell vial 1 mL</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">MSC basal medium</td>
			<td style="width:169px;">ATCC</td>
			<td style="width:307px;">ATCC PCS-500-030</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">MSC growth kit</td>
			<td style="width:169px;">ATCC</td>
			<td style="width:307px;">ATCC PCS-500-040</td>
			<td>Low serum</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">Chondrocyte differentiation tool</td>
			<td style="width:169px;">ATCC</td>
			<td style="width:307px;">ATCC PCS-500-051</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">Formalin solution</td>
			<td style="width:169px;">Sigma-Aldrich</td>
			<td style="width:307px;">HT5011-15ML</td>
			<td>neutral buffered, 10%</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:504px;">Ammonium chloride</td>
			<td style="width:169px;">Sigma-Aldrich</td>
			<td style="width:307px;">A9434-500G</td>
			<td>for molecular biology, suitable for cell culture, &#8805;99.5%</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">Saponin</td>
			<td style="width:169px;">Sigma-Aldrich</td>
			<td style="width:307px;">47036-50G-F</td>
			<td>for molecular biology, used as non-ionic surfactant, adjuvant</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:504px;">Bovine Serum Albumin (BSA)</td>
			<td style="width:169px;">Sigma-Aldrich</td>
			<td style="width:307px;">A3059-50G</td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:504px;">Rabbit monoclonal [Y113] anti-paxillin antibody</td>
			<td style="width:169px;">Abcam</td>
			<td style="width:307px;">ab32084</td>
			<td>Diluted 1:200</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">Mouse monoclonal [1F5] anti-collagen alpha-1 XX chain&#160;</td>
			<td style="width:169px;">Acris Antibodies</td>
			<td style="width:307px;">AM00212PU-N</td>
			<td>Diluted: 1:400</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:504px;">Alexa Fluor 488-conjugated goat anti-mouse IgG (H+L) secondary antibody</td>
			<td style="width:169px;">Invitrogen</td>
			<td style="width:307px;">A10667</td>
			<td>2 mg/mL. Diluted 1:1000</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">Alexa Fluor 568-conjugated goat anti-rabbit IgG (H+L) secondary antibody</td>
			<td style="width:169px;">Invitrogen</td>
			<td style="width:307px;">A11036</td>
			<td>2 mg/mL. Diluted 1:1000</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:504px;">Hoechst 33342</td>
			<td style="width:169px;">Thermo Fisher</td>
			<td style="width:307px;">H3570 10ML</td>
			<td>10 mg/mL. Diluted 1:1000</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">Cover glass 24x24 mm</td>
			<td style="width:169px;">Deltalab</td>
			<td style="width:307px;">D102424</td>
			<td></td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;width:504px;">Fluoromount</td>
			<td style="width:169px;">Sigma-Aldrich</td>
			<td style="width:307px;">F4680-25ML</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:504px;">Epifluorescence Microscope</td>
			<td style="width:169px;">Nikon</td>
			<td style="width:307px;">Eclipse E1000 upright microscope</td>
			<td>with a CCD camera</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:504px;">Confocal Microscope</td>
			<td style="width:169px;">Leica Microsystems</td>
			<td style="width:307px;"></td>
			<td>Leica SPE Upright Confocal Microscope</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">ImageJ 1.50g freeware</td>
			<td style="width:169px;">http://imgej.nih.gov/ij</td>
			<td style="width:307px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">MATLAB software</td>
			<td style="width:169px;">The MATHWORKS, Inc.</td>
			<td style="width:307px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:504px;">OriginPro 8.5 software&#160;</td>
			<td style="width:169px;">OriginLab Coorporation</td>
			<td style="width:307px;"></td>
			<td></td>
		</tr>
	</tbody>
</table>

dendrimer-based uneven nanopatterns to locally control surface adhesiveness: a method to direct chondrogenic differentiation

Cellular adhesion and differentiation is conditioned by the nanoscale disposition of the extracellular matrix (ECM) components, with local concentrations having a major effect. Here we present a method to obtain large-scale uneven nanopatterns of arginine-glycine-aspartic acid (RGD)-functionalized dendrimers that permit the nanoscale control of local RGD surface density. Nanopatterns are formed by surface adsorption of dendrimers from solutions at different initial concentrations and are characterized by water contact angle (CA), X-ray photoelectron spectroscopy (XPS), and scanning probe microscopy techniques such as scanning tunneling microscopy (STM) and atomic force microscopy (AFM). The local surface density of RGD is measured using AFM images by means of probability contour maps of minimum interparticle distances and then correlated with cell adhesion response and differentiation. The nanopatterning method presented here is a simple procedure that can be scaled up in a straightforward manner to large surface areas. It is thus fully compatible with cell culture protocols and can be applied to other ligands that exert concentration-dependent effects on cells.

We present a nanopatterning method that allows surface adhesiveness to be addressed at the nanoscale (Figure 1). The chemical structure of RGD-Cys-D1 is shown in Figure 1A. Dendrimers were patterned on electrical conductive Au(111) surfaces for high resolution STM characterization. Low dendrimer concentrations in solution (up to 10-5% w/w) rendered isolated dendrimers of 4-5 nm in diameter (<strong class="xfig...

Watch this Scientific Journal Video about Dendrimer-based Uneven Nanopatterns to Locally Control Surface Adhesiveness: A Method to Direct Chondrogenic Differentiation at JoVE.com

Dendrimer-based Uneven Nanopatterns to Locally Control Surface Adhesiveness: A Method to Direct Chondrogenic Differentiation

A method to obtain dendrimer-based uneven nanopatterns that permit the nanoscale control of local arginine-glycine-aspartic acid (RGD) surface density is described and applied for the study of cell adhesion and chondrogenic differentiation.

Cellular adhesion and differentiation is conditioned by the nanoscale disposition of the extracellular matrix (ECM) components, with local concentrations ...

Research

JoVE Journal

Bioengineering

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