ABSTRACT
The regeneration of bone via a tissue engineering approach involves components from the macroscopic to the nanoscopic level, including appropriate 3D scaffolds, cells and growth factors. In this study, hexagonal scaffolds of different diagonals were fabricated by Direct Laser Writing using a photopolymerizable hybrid material. The proliferation of bone marrow (BM) mesenchymal stem cells (MSCs) cultured on structures with various diagonals, 50, 100, 150 and 200µm increased significantly after 10days in culture, however without significant differences among them. Next, recombinant human bone morphogenetic protein 2 (rhBMP-2) was immobilized onto the hybrid material both via covalent binding and physical adsorption. Both immobilization types exhibited similar high releaseate bioactivity profiles and a sustained delivery of rhBMP-2. The collagen and calcium levels produced in the extracellular matrix (ECM) were significantly elevated for the samples functionalized with BMP-2 compared to those in the osteogenic medium. Furthermore, significant upregulation of gene expression in both types of BMP-2 immobilized scaffolds was observed for alkaline phosphatase (ALPL) and osteocalcin (BGLAP) at days 7, 14, and 21, for RUNX2 at day 21, and for osteonectin (SPARC) at days 7 and 14. The results suggest that the release of bioactive rhBMP-2 from the hybrid scaffolds enhance the control over the osteogenic differentiation during cell culture.
Subject(s)
Bone Marrow Cells/drug effects , Bone Morphogenetic Protein 2/pharmacology , Mesenchymal Stem Cells/drug effects , Osteogenesis/drug effects , Tissue Scaffolds , Adsorption , Alkaline Phosphatase/genetics , Alkaline Phosphatase/metabolism , Bone Marrow Cells/cytology , Bone Marrow Cells/metabolism , Bone Morphogenetic Protein 2/genetics , Bone Morphogenetic Protein 2/metabolism , Cell Differentiation/drug effects , Cell Proliferation/drug effects , Collagen/genetics , Collagen/metabolism , Core Binding Factor Alpha 1 Subunit/genetics , Core Binding Factor Alpha 1 Subunit/metabolism , Extracellular Matrix/drug effects , Extracellular Matrix/metabolism , Gene Expression Regulation , Humans , Immobilized Proteins/genetics , Immobilized Proteins/metabolism , Immobilized Proteins/pharmacology , Lasers , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/metabolism , Osteocalcin/genetics , Osteocalcin/metabolism , Osteogenesis/genetics , Osteonectin/genetics , Osteonectin/metabolism , Primary Cell Culture , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Recombinant Proteins/pharmacology , Tissue EngineeringABSTRACT
We explore the excitation of plasmons in 3D plasmon crystal metamaterials and report the observation of a delocalized plasmon mode, which provides extremely high spectral sensitivity (>2600 nm per refractive index unit (RIU) change), outperforming all plasmonic counterparts excited in 2D nanoscale geometries, as well as a prominent phase-sensitive response (>3*10(4) deg. of phase per RIU). Combined with a large surface for bioimmobilization provided by the 3D matrix, the proposed sensor architecture promises a new important landmark in the advancement of plasmonic biosensing technology.
Subject(s)
Biosensing Techniques/methodsABSTRACT
The self-assembly of short peptides into fibrous nanostructures (such as fibrils and tubes) has recently become the subject of intense theoretical and experimental scrutiny, as such assemblies are promising candidates for nanobiotechnological applications. The sequences of natural fibrous proteins may provide a rich source of inspiration for the design of such short self-assembling peptides. We describe the self-assembly of the aspartate-rich undecapeptide (NH3(+)-LSGSDSDTLTV-NH2), a sequence derived from the shaft of the adenovirus fiber. We demonstrate that the peptide assembles experimentally into amyloid-type fibrils according to widely accepted diagnostic criteria. In addition, we investigate an aqueous solution of undecapeptides by molecular dynamics simulations with an implicit (GB) solvent model. The peptides are frequently arranged in intermolecular ß-sheets, in line with their amyloidogenic propensity. On the basis of both experimental and theoretical insights, we suggest possible structural models of the fibrils and their potential use as scaffolds for templating of inorganic materials.
Subject(s)
Aspartic Acid/chemistry , Capsid Proteins/chemistry , Nanostructures/chemistry , Oligopeptides/chemistry , Amyloid/chemistry , Microscopy, Atomic Force , Microscopy, Electron, Transmission , Models, Molecular , Molecular Dynamics Simulation , Nanostructures/ultrastructure , Probability , Protein Structure, Secondary , Serine/chemistry , Solutions , Solvents/chemistry , Water/chemistry , X-Ray DiffractionABSTRACT
In this study, we propose a new approach to hard tissue regeneration based on the mineralization of 3D scaffolds made using lasers. To this end, we report the rational design of aspartate-containing self-assembling peptides targeted for calcium binding. We further investigate the suitability of these peptides to support cell attachment and proliferation when coupled on a hybrid organic-inorganic structurable material, and evaluate the response of pre-osteoblastic cells on functionalized 3D scaffolds and material surfaces. Our results show that the mineralized peptide, when immobilized on a hybrid photo-structurable material strongly supports cell adhesion, a proliferation increase after three and seven days in culture, and exhibits a statistically significant increase of biomineralization. We propose this strategy as a 'scaffold on scaffold' approach for hard tissue regeneration.
Subject(s)
Peptides/chemistry , Peptides/pharmacology , Tissue Engineering/methods , Tissue Scaffolds , Amyloid/chemistry , Amyloid/metabolism , Animals , Aspartic Acid , Calcium/metabolism , Calcium Phosphates/metabolism , Cell Physiological Phenomena/drug effects , Cells, Cultured , Mice , Osteoblasts/cytology , Osteoblasts/metabolism , Peptides/metabolismABSTRACT
Engineering artificial scaffolds that enhance cell adhesion and growth in three dimensions is essential to successful bone tissue engineering. However, the fabrication of three-dimensional (3D) tissue scaffolds exhibiting complex micro- and nano-features still remains a challenge. Few materials can be structured in three dimensions, and even those have not been characterized for their mechanical and biological properties. In this study, we investigate the suitability of three novel materials of different chemical compositions in bone tissue regeneration: a hybrid material consisting of methacryloxypropyl trimethoxysilane and zirconium propoxide, a hybrid organic-inorganic material of the above containing 50 mole% 2-(dimethylamino)ethyl methacrylate (DMAEMA) and a pure organic material based on polyDMAEMA. More specifically, we study the mechanical properties of the aforementioned materials and evaluate the biological response of pre-osteoblastic cells on them. We also highlight the use of a 3D scaffolding technology, Direct femtosecond Laser Writing (DLW), to fabricate complex structures. Our results show that, while all three investigated materials could potentially be used as biomaterials in tissue engineering, the 50% DMAEMA composite exhibits the best mechanical properties for structure fabrication with DLW and strong biological response.
Subject(s)
Osteoblasts/cytology , Tissue Engineering/methods , Tissue Scaffolds/chemistry , 3T3 Cells , Animals , Bone Regeneration , Bone and Bones/cytology , Bone and Bones/physiology , Cell Adhesion , Cell Proliferation , MiceABSTRACT
The fabrication of fully three-dimensional photonic crystals with a bandgap at optical wavelengths is demonstrated by way of direct femtosecond laser writing of an organic-inorganic hybrid material with metal-binding moieties, and selective silver coating using electroless plating. The crystals have 600-nm intralayer periodicity and sub-100 nm features, and they exhibit well-defined diffraction patterns.
