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Novel opportunities and challenges offered by nanobiomaterials in tissue engineering.

Gelain F - Int J Nanomedicine (2008)

Bottom Line: Still reliable synthetic scaffolds fairly resembling the nanostructure of extracellular matrices, showing mechanical properties comparable to those of the tissues to be regenerated and capable of being modularly functionalized with biological active motifs, became feasible only in the last years thanks to newly introduced nanotechnology techniques of material design, synthesis, and characterization.Nanostructured synthetic matrices look to be the next generation scaffolds, opening new powerful pathways for tissue regeneration and introducing new challenges at the same time.We here present a detailed overview of the advantages, applications, and limitations of nanostructured matrices with a focus on both electrospun and self-assembling scaffolds.

View Article: PubMed Central - PubMed

Affiliation: Bioscience and Biotechnology Department, University of Milan-Bicocca, Milan, Italy. fabrizio.gelain@unimib.it

ABSTRACT
Over the last decades, tissue engineering has demonstrated an unquestionable potential to regenerate damaged tissues and organs. Some tissue-engineered solutions recently entered the clinics (eg, artificial bladder, corneal epithelium, engineered skin), but most of the pathologies of interest are still far from being solved. The advent of stem cells opened the door to large-scale production of "raw living matter" for cell replacement and boosted the overall sector in the last decade. Still reliable synthetic scaffolds fairly resembling the nanostructure of extracellular matrices, showing mechanical properties comparable to those of the tissues to be regenerated and capable of being modularly functionalized with biological active motifs, became feasible only in the last years thanks to newly introduced nanotechnology techniques of material design, synthesis, and characterization. Nanostructured synthetic matrices look to be the next generation scaffolds, opening new powerful pathways for tissue regeneration and introducing new challenges at the same time. We here present a detailed overview of the advantages, applications, and limitations of nanostructured matrices with a focus on both electrospun and self-assembling scaffolds.

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Related in: MedlinePlus

SEM imaging of a cluster of neural stem cells cultured in a RADA16-I-BMHP1 self-assembled scaffold. Low- (A) and high-magnification (B) images highlight cell bodies partially but tightly wrapped with functionalized nanofibers.
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f3-ijn-3-415: SEM imaging of a cluster of neural stem cells cultured in a RADA16-I-BMHP1 self-assembled scaffold. Low- (A) and high-magnification (B) images highlight cell bodies partially but tightly wrapped with functionalized nanofibers.

Mentions: Different functional motifs can be incorporated in various ratios in the same scaffold if the self-assembling “core” is maintained regardless of the functionalization itself. We functionalized self-assembling scaffolds with bone marrow homing peptides (Gelain et al 2006), functional motifs discovered to be particularly promising for stimulating NSC adhesion and differentiation (see Figure 2). Biomaterial functionalization is usually achieved for flat or grooved surfaces and microstructured scaffolds: just recently PLGA or PCL nanofibers became commercially available for functionalization with a limited number of biological motifs via a biochemical process involving potentially harmful chemicals and, most importantly, far from being adopted to tightly embed living cells in a functionalized 3D matrix. Indeed self-assembling scaffolds show the unquestionable synergic advantages of both spontaneously forming scaffolds embedding cells, thus placing functional motifs close to cell membrane receptors, and selectively stimulating diverse cell signaling pathways by choosing various sets of functional motifs to be included in the 3D scaffold nanostructures (see Figure 3). In 3D scaffolds, cells receive more dense and evenly distributed amount of functional motifs available for cell membrane receptor binding than when in contact with coated 2D RGD-coated surfaces or microfibers. A specific set of different motifs can be easily tested for selective gene expression activation: for example, we evidenced how neural stem cells differentiation in BMHP1 functionalized scaffolds highly increased the mRNA expression of Laminin-b2 and Fibulin 1 genes, both proteins involved in ECM assembly, suggesting the existence of a possible common pathway activation. Similar selective stimulations cannot be obtained, and neither tuned, with any biologically derived substrates used for in vitro neural cultures. This and other studies may uncover new insights into cell expression mechanisms powerful for basic science purposes.


Novel opportunities and challenges offered by nanobiomaterials in tissue engineering.

Gelain F - Int J Nanomedicine (2008)

SEM imaging of a cluster of neural stem cells cultured in a RADA16-I-BMHP1 self-assembled scaffold. Low- (A) and high-magnification (B) images highlight cell bodies partially but tightly wrapped with functionalized nanofibers.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2636587&req=5

f3-ijn-3-415: SEM imaging of a cluster of neural stem cells cultured in a RADA16-I-BMHP1 self-assembled scaffold. Low- (A) and high-magnification (B) images highlight cell bodies partially but tightly wrapped with functionalized nanofibers.
Mentions: Different functional motifs can be incorporated in various ratios in the same scaffold if the self-assembling “core” is maintained regardless of the functionalization itself. We functionalized self-assembling scaffolds with bone marrow homing peptides (Gelain et al 2006), functional motifs discovered to be particularly promising for stimulating NSC adhesion and differentiation (see Figure 2). Biomaterial functionalization is usually achieved for flat or grooved surfaces and microstructured scaffolds: just recently PLGA or PCL nanofibers became commercially available for functionalization with a limited number of biological motifs via a biochemical process involving potentially harmful chemicals and, most importantly, far from being adopted to tightly embed living cells in a functionalized 3D matrix. Indeed self-assembling scaffolds show the unquestionable synergic advantages of both spontaneously forming scaffolds embedding cells, thus placing functional motifs close to cell membrane receptors, and selectively stimulating diverse cell signaling pathways by choosing various sets of functional motifs to be included in the 3D scaffold nanostructures (see Figure 3). In 3D scaffolds, cells receive more dense and evenly distributed amount of functional motifs available for cell membrane receptor binding than when in contact with coated 2D RGD-coated surfaces or microfibers. A specific set of different motifs can be easily tested for selective gene expression activation: for example, we evidenced how neural stem cells differentiation in BMHP1 functionalized scaffolds highly increased the mRNA expression of Laminin-b2 and Fibulin 1 genes, both proteins involved in ECM assembly, suggesting the existence of a possible common pathway activation. Similar selective stimulations cannot be obtained, and neither tuned, with any biologically derived substrates used for in vitro neural cultures. This and other studies may uncover new insights into cell expression mechanisms powerful for basic science purposes.

Bottom Line: Still reliable synthetic scaffolds fairly resembling the nanostructure of extracellular matrices, showing mechanical properties comparable to those of the tissues to be regenerated and capable of being modularly functionalized with biological active motifs, became feasible only in the last years thanks to newly introduced nanotechnology techniques of material design, synthesis, and characterization.Nanostructured synthetic matrices look to be the next generation scaffolds, opening new powerful pathways for tissue regeneration and introducing new challenges at the same time.We here present a detailed overview of the advantages, applications, and limitations of nanostructured matrices with a focus on both electrospun and self-assembling scaffolds.

View Article: PubMed Central - PubMed

Affiliation: Bioscience and Biotechnology Department, University of Milan-Bicocca, Milan, Italy. fabrizio.gelain@unimib.it

ABSTRACT
Over the last decades, tissue engineering has demonstrated an unquestionable potential to regenerate damaged tissues and organs. Some tissue-engineered solutions recently entered the clinics (eg, artificial bladder, corneal epithelium, engineered skin), but most of the pathologies of interest are still far from being solved. The advent of stem cells opened the door to large-scale production of "raw living matter" for cell replacement and boosted the overall sector in the last decade. Still reliable synthetic scaffolds fairly resembling the nanostructure of extracellular matrices, showing mechanical properties comparable to those of the tissues to be regenerated and capable of being modularly functionalized with biological active motifs, became feasible only in the last years thanks to newly introduced nanotechnology techniques of material design, synthesis, and characterization. Nanostructured synthetic matrices look to be the next generation scaffolds, opening new powerful pathways for tissue regeneration and introducing new challenges at the same time. We here present a detailed overview of the advantages, applications, and limitations of nanostructured matrices with a focus on both electrospun and self-assembling scaffolds.

Show MeSH
Related in: MedlinePlus