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ABSTRACT: The aim of this study was to evaluate potential effects of DNA-coatings on calcium phosphate (CaP) nucleation from simulated body fluids (SBF) and subsequently the effects of DNA-coatings and SBF-immersed DNA coatings on the behavior of osteoblast-like cells. DNA-coatings demonstrated to enhance the nucleation and deposition of Cap from SBF compared to titanium controls. The behavior of osteoblast-like cells was affected on SBF-immersed DNA-coatings, showing an increased deposition of the extracellular matrix protein osteocalcin compared to titanium controls. These results indicate bone-bonding capacity of DNA-coatings, which needs to be confirmed using future animal experiments.
01/2008: pages 605-608;
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ABSTRACT: This study describes the effect of multilayered DNA coatings on (i) the formation of mineralized depositions from simulated body fluids (SBF); and (ii) osteoblast-like cell behavior with and without pretreatment in SBF. DNA coatings were generated using electrostatic self-assembly, with poly-d-lysine or poly(allylamine hydrochloride) as cationic polyelectrolytes, on titanium substrates. Coated substrates and non-coated controls were immersed in SBF with various compositions. The deposition of calcium phosphate was enhanced on multilayered DNA coatings as compared with non-coated controls, and was dependent on the type of cationic polyelectrolyte used in the build-up of the DNA coatings. Further analysis showed that the depositions consisted of carbonated apatite. Non-pretreated DNA coatings were found to have no effect on osteoblast-like cell behavior compared with titanium controls. On the other hand, SBF-pretreatment of DNA coatings affected the differentiation of osteoblast-like cells through an increased deposition of osteocalcin. The results of this study are indicative of the bone-bonding capacities of DNA coatings. Nevertheless, future animal experiments are required to provide conclusive evidence for the bioactivity of DNA coatings.
Acta Biomaterialia 08/2007; 3(4):587-96. · 4.86 Impact Factor
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ABSTRACT: This study was performed to evaluate the basic biological response to deoxyribonucleic acid (DNA)-based coatings for soft tissue implants. To that end, in vitro experiments were used to study their cytocompatibility, and in vivo subcutaneous implantation studies with transponders in a rat model were performed to evaluate their histocompatibility. The DNA-based coatings were fabricated using the electrostatic self-assembly technique using cationic poly-D-lysine or poly-allylamine hydrochloride and anionic DNA. Noncoated substrates served as controls. In vitro, the behavior of primary rat dermal fibroblasts was assessed in terms of cell proliferation and morphology. Both types of multilayered DNA-coatings significantly increased rat dermal fibroblast proliferation without altering the morphological appearance of the cells. The tissue response to multilayered DNA-coatings was assessed using an in vivo rat model, in which transponders were inserted subcutaneously for 4 and 12 weeks. No macroscopic signs of inflammation or adverse tissue reactions were observed at implant retrieval. Histological analyses demonstrated a uniform tissue response to all types of implants. All implants were encapsulated in a fibrous tissue capsule without intervening inflammatory cells at the implant surface. Histomorphometrically, multilayered DNA-coatings induced fibrous tissue capsules with similar quality and thickness compared to noncoated controls. In addition, all fibrous tissue capsules showed similar expression of alpha-smooth muscle actin. This study demonstrates that multilayered DNA-coatings are cytocompatible and histocompatible, and justifies further research on their functionalization with biologically active compounds to modulate tissue responses.
Journal of Biomedical Materials Research Part B Applied Biomaterials 05/2007; 81(1):231-8. · 2.15 Impact Factor
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ABSTRACT: A pivotal factor to consider in the development of biomaterials and biomaterial coatings is the inflammatory response to these materials. The insertion of implants is followed by protein adsorption and subsequent interactions with cellular components of the biological surroundings, in which macrophages play a dominant role through the production of a myriad of signaling molecules. In view of this, the aims of the present study were to evaluate (i) gross protein adsorption to, and (ii) in vitro behavior of macrophages on novel biomaterial coatings, composed of poly-D-lysine (PDL) or poly(allylamine hydrochloride) (PAH) and DNA, and to compare these coatings with negative (noncoated glass) and positive controls (noncoated glass + LPS-stimulation). The results demonstrate that multilayered DNA-coatings do not affect gross protein adsorption compared to noncoated controls. Cell culture experiments showed that the attachment to, and viability and morphology of two types of macrophages cultured on multilayered DNA-coatings is comparable to noncoated controls. Still, macrophages repeatedly showed decreased secretion levels of the proinflammatory cytokine TNF-alpha on multilayered DNA-coatings, whereas no differences were observed in the secretion of IL-1beta, IL-10, and TGF-beta1. Appropriate animal studies are required to elucidate if these in vitro indications have clinical effects on the inflammatory and wound healing processes around implants.
Journal of Biomedical Materials Research Part A 04/2007; 80(3):612-20. · 2.63 Impact Factor
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ABSTRACT: A pivotal factor to consider in the development of biomaterials and biomaterial coatings is the inflammatory response to these materials. The insertion of implants is followed by protein adsorption and subsequent interactions with cellular components of the biological surroundings, in which macrophages play a dominant role through the production of a myriad of signaling molecules. In view of this, the aims of the present study were to evaluate (i) gross protein adsorption to, and (ii) in vitro behavior of macrophages on novel biomaterial coatings, composed of poly-D-lysine (PDL) or poly(allylamine hydrochloride) (PAH) and DNA, and to compare these coatings with negative (noncoated glass) and positive controls (noncoated glass + LPS-stimulation). The results demonstrate that multilayered DNA-coatings do not affect gross protein adsorption compared to noncoated controls. Cell culture experiments showed that the attachment to, and viability and morphology of two types of macrophages cultured on multilayered DNA-coatings is comparable to noncoated controls. Still, macrophages repeatedly showed decreased secretion levels of the proinflammatory cytokine TNF- on multilayered DNA-coatings, whereas no differences were observed in the secretion of IL-1β, IL-10, and TGF-β1. Appropriate animal studies are required to elucidate if these in vitro indications have clinical effects on the inflammatory and wound healing processes around implants. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Journal of Biomedical Materials Research Part A 02/2007; 80A(3):612 - 620. · 2.63 Impact Factor
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ABSTRACT: Synthetic, bio-inspired organic-inorganic composites are emerging as new materials for bone regeneration, offering more possibilities to tune biocompatibility, biodegradability and mechanical properties. Also thin films of calcium carbonate have been shown to have potential as models for bone replacement biomaterials. These calcium carbonate thin films can be formed using anionic macromolecules as a crystallization inhibitor. Here we demonstrate that also DNA is a powerful inhibitor of calium carbonate crystallization which can be used to prepare amorphous films that slowly crystallize to form calcite with a preferred (11.0) orientation. We show that the DNA-based hybrid material can be grown as inorganic coatings on polymer substrates of high molecular weight polyethylene and poly( caprolactone). The layer-by-layer deposition of a DNA-surfactant double layer was used as an interfacial layer minimizing the observed polymer specific surface roughness. This coating increased the crystallization rate but did not affect the preferred ( 11.0) orientation. Using this technique we were able to apply this coating as a smooth calcium carbonate coating on the surface of a porous 3D polycaprolactone scaffold.
CrystEngComm 01/2007; 9(12):1209-1214. · 3.84 Impact Factor
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ABSTRACT: The focus of the present study was to functionalize multilayered DNA-coatings with the osteoinductive factor bone morphogenetic protein 2 (BMP-2) using different loading modalities. The multilayered DNA-coatings were built up from either poly-d-lysine (PDL) or poly(allylamine hydrochloride) (PAH) and DNA using electrostatic self-assembly (ESA). The amounts of BMP-2 loaded into the multilayered DNA-coatings and its subsequent release characteristics were determined using radiolabeled BMP-2. Additionally, the effect of BMP-2 functionalized multilayered DNA-coatings on the in vitro behavior of bone marrow-derived osteoblast-like cells was evaluated in terms of proliferation, differentiation, mineralization, and cell morphology. The results demonstrate the feasibility of multilayered DNA-coatings to be functionalized by embedding BMP-2 according to three different loading modalities: superficial (s), deep (d), and double-layer (dl). BMP-2 was incorporated proportionally into the multilayered DNA-coatings as: s+(4*d)=dl. All differently loaded multilayered DNA-coatings showed an initial burst release followed by an incremental sustained release of the remaining BMP-2. In vitro experiments demonstrated that the loaded factor remained biologically active, as an accelerated calcium deposition was observed on s- and dl-loaded multilayered DNA-coatings, without affecting cell proliferation. In contrast, d-loaded multilayered DNA-coatings influenced osteoblast-like cell behavior by decreasing the deposition of calcium.
Journal of Controlled Release 07/2006; 113(1):63-72. · 5.73 Impact Factor
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ABSTRACT: DNA-containing biomaterial coatings offer potential beneficial effects for both soft and hard tissue implants because of the structural properties of DNA. In the current study, the aim was to assess the in vitro cyto- and in vivo histocompatibility of multilayered DNA-coatings generated using the electrostatic self-assembly technique, with poly-D-lysine or poly(allylamine hydrochloride) as the cationic counterparts of anionic DNA. Multilayered DNA-coatings were fabricated on titanium substrates. Noncoated titanium substrates served as controls. In vitro experiments with rat primary dermal fibroblasts (RDF) assessing their viability were performed using a Live/Dead assay and an MTT-based assay. The presence of multilayered DNA-coatings did not affect RDF cell viability. On the other hand, an increased proliferation was demonstrated on both types of multilayered DNA-coatings. An in vivo rat model was used to study the soft tissue histocompatibility of subcutaneously inserted implants during implantation periods of 4 and 12 weeks. Light microscopic analysis revealed that all implants were surrounded by a fibrous capsule containing alpha-smooth muscle actin, and that the presence of a multilayered DNA-coating did not induce any adverse effects in terms of inflammation and wound healing. Histomorphometrically, no significant differences in capsule quality or thickness were observed dependent on multilayered DNA-coating or implantation period. The cyto- and histocompatibility of multilayered DNA-coatings demonstrated in this study allows their use and functionalization with appropriate compounds to modulate cell and tissue responses in dental and medical implantology.
Journal of Biomedical Materials Research Part A 05/2006; 77(1):202-11. · 2.63 Impact Factor
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ABSTRACT: DNA-containing biomaterial coatings offer potential beneficial effects for both soft and hard tissue implants because of the structural properties of DNA. In the current study, the aim was to assess the in vitro cyto- and in vivo histocompatibility of multilayered DNA-coatings generated using the electrostatic self-assembly technique, with poly-D-lysine or poly(allylamine hydrochloride) as the cationic counterparts of anionic DNA. Multilayered DNA-coatings were fabricated on titanium substrates. Noncoated titanium substrates served as controls. In vitro experiments with rat primary dermal fibroblasts (RDF) assessing their viability were performed using a Live/Dead assay and an MTT-based assay. The presence of multilayered DNA-coatings did not affect RDF cell viability. On the other hand, an increased proliferation was demonstrated on both types of multilayered DNA-coatings. An in vivo rat model was used to study the soft tissue histocompatibility of subcutaneously inserted implants during implantation periods of 4 and 12 weeks. Light microscopic analysis revealed that all implants were surrounded by a fibrous capsule containing -smooth muscle actin, and that the presence of a multilayered DNA-coating did not induce any adverse effects in terms of inflammation and wound healing. Histomorphometrically, no significant differences in capsule quality or thickness were observed dependent on multilayered DNA-coating or implantation period. The cyto- and histocompatibility of multilayered DNA-coatings demonstrated in this study allows their use and functionalization with appropriate compounds to modulate cell and tissue responses in dental and medical implantology. © 2005 Wiley Periodicals, Inc. J. Biomed. Mater. Res, 2006.
Journal of Biomedical Materials Research Part A 03/2006; 77A(1):202 - 211. · 2.63 Impact Factor
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ABSTRACT: This study describes the effect of multilayered DNA coatings on (i) the formation of mineralized depositions from simulated body fluids (SBF); and (ii) osteoblast-like cell behavior with and without pretreatment in SBF. DNA coatings were generated using electrostatic self-assembly, with poly-d-lysine or poly(allylamine hydrochloride) as cationic polyelectrolytes, on titanium substrates. Coated substrates and non-coated controls were immersed in SBF with various compositions. The deposition of calcium phosphate was enhanced on multilayered DNA coatings as compared with non-coated controls, and was dependent on the type of cationic polyelectrolyte used in the build-up of the DNA coatings. Further analysis showed that the depositions consisted of carbonated apatite. Non-pretreated DNA coatings were found to have no effect on osteoblast-like cell behavior compared with titanium controls. On the other hand, SBF-pretreatment of DNA coatings affected the differentiation of osteoblast-like cells through an increased deposition of osteocalcin. The results of this study are indicative of the bone-bonding capacities of DNA coatings. Nevertheless, future animal experiments are required to provide conclusive evidence for the bioactivity of DNA coatings.
Acta Biomaterialia.
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ABSTRACT: The focus of the present study was to functionalize multilayered DNA-coatings with the osteoinductive factor bone morphogenetic protein 2 (BMP-2) using different loading modalities. The multilayered DNA-coatings were built up from either poly-d-lysine (PDL) or poly(allylamine hydrochloride) (PAH) and DNA using electrostatic self-assembly (ESA). The amounts of BMP-2 loaded into the multilayered DNA-coatings and its subsequent release characteristics were determined using radiolabeled BMP-2. Additionally, the effect of BMP-2 functionalized multilayered DNA-coatings on the in vitro behavior of bone marrow-derived osteoblast-like cells was evaluated in terms of proliferation, differentiation, mineralization, and cell morphology. The results demonstrate the feasibility of multilayered DNA-coatings to be functionalized by embedding BMP-2 according to three different loading modalities: superficial (s), deep (d), and double-layer (dl). BMP-2 was incorporated proportionally into the multilayered DNA-coatings as: s + (4 ⁎ d) = dl. All differently loaded multilayered DNA-coatings showed an initial burst release followed by an incremental sustained release of the remaining BMP-2. In vitro experiments demonstrated that the loaded factor remained biologically active, as an accelerated calcium deposition was observed on s- and dl-loaded multilayered DNA-coatings, without affecting cell proliferation. In contrast, d-loaded multilayered DNA-coatings influenced osteoblast-like cell behavior by decreasing the deposition of calcium.
Journal of Controlled Release.
