Nagel MD, Verhoef R, Schols H, Morra M, Knox JP, Ceccone G, Della Volpe C, Vigneron P,
Bussy C, Gallet M, Velzenberger E, Vayssade M, Cascardo G, Cassinelli C, Haeger A, Gilliland D,
Liakos I, Rodriguez-Valverde M, Siboni S.

Biochimica et Biophysica Acta, General subjects, accepted 18 April 2008.
Submit Date: Feb 12, 2008

Modulating in vitro bone cell and macrophage behavior
by immobilized enzymatically tailored pectins.

Bussy C, Verhoef R, Haeger A, Morra M, Duval JL, Vigneron P, Bensoussan A, Velzenberger E,
Cascardo G, Cassinelli C, Schols H, Knox JP, Nagel MD.

Domaine Biomatériaux‐Biocompatibilité, UMR CNRS 6600, Université de Technologie de Compiègne, France.

SUMMARY:
Previous work has reported the results of a multidisciplinary effort producing a proof-of-concept on the use of pectic polysaccharides in the surface modification of medical devices. This study was designed to learn more about the capability of engineered rhamnogalacturonan-I (RG-I) fractions of apple pectin to control bone cell and macrophage behavior. Thermanox(R) or polystyrene Petri dishes were surface modified with two different modified hairy regions (MHRs) obtained by different enzymatic liquefaction processes of apples differing in relative amounts and lengths of their neutral side chains: (long-haired) MHR-alpha and (short-haired) MHR-B. Bone explants from 14-day-old chick embryos were cultured for 14 days on both pectic substrata. MHR-B promoted cell migration and differentiation, MHR-alpha did not. On MHR-alpha, J774.2 macrophages grew well, their percentage in G1 phase was decreased and in S phase increased, and they did not secrete either proinflammatory-cytokines or nitrites. Contrasting results were gained from macrophages on MHR-B, except for nitrite secretion. Thus, we conclude that coatings from tailored pectins show different biological activities in vitro and are potential innovative candidates for improving the biocompatibility of medical devices in various applications. (c) 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007.

SOURCE:
Pubmed.gov website

Effect of modified pectin molecules
on the growth of bone cells.

SUMMARY:
The aim of this study was to investigate molecular candidates for bone implant nanocoatings, which could improve biocompatibility of implant materials. Primary rat bone cells and murine preosteoblastic MC3T3-E1 cells were cultured on enzymatically modified hairy regions (MHR-A and MHR-B) of apple pectins. MHRs were covalently attached to tissue culture polystyrene (TCPS) or glass. Uncoated substrata or bone slices were used as controls. Cell attachment, proliferation, and differentiation were investigated with fluorescence and confocal microscopy. Bone cells seem to prefer MHR-B coating to MHR-A coating. On MHR-A samples, the overall numbers as well as proportions of active osteoclasts were diminished compared to those on MHR-B, TCPS, or bone. Focal adhesions indicating attachment of the osteoblastic cells were detected on MHR-B and uncoated controls but not on MHR-A. These results demonstrate the possibility to modify surfaces with pectin nanocoatings.

SOURCE:
Pubmed.gov website

First published article of the Pecticoat consortium 

P. Biomacromolecules, 5: 2094-2104, 2004. 

"Effects on interfacial properties and cell adhesion of  surface modification by pectic
hairy regions”
MORRA M., CASSINELLI C., CASCADO G., NAGEL MD., DELLA VOLPE C., SIBONI S., MANIGLIO D.,
BRUGNARA M., CECCONE G., SCHOLS H., ULVSKOV

SUMMARY:
Polystyrene Petri dishes, aminated by a plasma deposition process, were surface modified by the covalent linking of two different enzymatically modified hairy regions (HRs) from pectin containing, for example, rhamnogalacturonan-I and xylogalacturonan structural elements. The two polysaccharide preparations share the same structural elements of apple pectin, but the relative amounts and lengths of the neutral side chains present differ. Surface analysis by X-ray photoelectron spectroscopy, contact angle measurement, and atomic force microscope (AFM) force-separation curves was used to characterize the effects on surface chemistry and interfacial forces of the surface modification process. Cell adhesion experiments using continuous L-929 fibroblasts and primary aortic smooth muscle cells were performed to evaluate the effect of the polysaccharide nature on cell adhesion. Results show that immobilization of the HR affects the interfacial field of forces and the cell behavior: "equilibrium" contact angles, obtained by a recently introduced vibrational approach, decrease after HR immobilization reaching a value close to 20 degrees . AFM force-separation curves show a more extended (or softer) interface in the case of the HR bearing longer side chains. Accordingly, depending on the HR preparation, cells shifted from spread morphology and adhesion behavior quantitatively comparable to that observed on conventional tissue culture polystyrene to rounded morphology and significantly lower adhesion. These data show that engineering of plant pectins can be a valuable tool to prepare novel and finely tuned polysaccharides having different chemico-physical and biological properties, to be used in the surface modification of medical devices and materials.

SOURCE:
Pubmed website