This work reports the synthesis of polymeric hybrids based on Casein and 2-hydroxyethyl methacryl... more This work reports the synthesis of polymeric hybrids based on Casein and 2-hydroxyethyl methacrylate polymers (PHEMA). Protein physical immobilization during the free-radical polymerization was performed. Two strategies were used to generate both films and cylinders. The homogeneity and the stability of the hybrids were assessed as well as their capacity to perform in vitro calcification when incubated in synthetic human plasma (SBF) for 14 days. Nucleation islets of calcium phosphate mineral in the form of nanometric nodules (20-30 nm) were observed on the Cas-rich domains. This study reports for the first time the synthesis of Cas-PHEMA materials and it tried to determine if these hybrids could cause a calcification under in vitro conditions.
Half of the annual human deaths worldwide are due to cardiovascular diseases [1]. Currently, synt... more Half of the annual human deaths worldwide are due to cardiovascular diseases [1]. Currently, synthetic grafts play a vital role in medicine, as implant demands exceed natural available sources and thus alternative solutions are needed. Poly(ethylene terephthalate) or PET is extensively used as a synthetic graft material on account of its excellent bulk properties (high mechanical and thermal properties) and chemical inertness. A major drawback is its poor surface properties that directly influence biological performance. Herein, we present a nature-inspired surface modification strategy suitable for fine-tuning surface properties of PET grafts. Materials & Methods. A two-step surface modification strategy was applied to PET (see Fig 1.). A dopamine-based coating procedure was used to facilitate the subsequent covalent immobilization of gelatin. In parallel, physisorbed surfaces were obtained by dip-coating. A surface characterization was performed using SCA, AFM and XPS, coupled wit...
The potential in vascular grafts of gelatin-modified poly(ethylene terephthalate) (PET) was shown... more The potential in vascular grafts of gelatin-modified poly(ethylene terephthalate) (PET) was shown herein via their coating stability, ability to promote endothelial cells (ECs) and smooth muscle cells (SMCs) and positive cyto- and endotoxicity assessments.
In vascular tissue engineering, great attention is paid to the immobilization of biomolecules ont... more In vascular tissue engineering, great attention is paid to the immobilization of biomolecules onto synthetic grafts to increase bio- and hemocompatibility-two critical milestones in the field. The surface modification field of poly(ethylene terephthalate) (PET), a well-known vascular-graft material, is matured and oversaturated. Nevertheless, most developed methods are laborious multistep procedures generally accompanied by coating instability or toxicity issues. Herein, a straightforward surface modification procedure is presented engineered to simultaneously promote surface endothelialization and anticoagulation properties via the covalent immobilization of gelatin through a photoactivated azide derivative. A complete physicochemical characterization and biological study including cytotoxicity and endotoxin testing are performed. In addition, biocompatibility toward small (diameter ≤ 6 mm) and/or large caliber (diameter ≥ 6 mm) vessels is assessed by micro- and macrovascular endot...
An aqueous-based bio-inspired approach was applied to chemically bind a bio compatible and cell-i... more An aqueous-based bio-inspired approach was applied to chemically bind a bio compatible and cell-interactive gelatin layer on poly(ethylene terephthalate) (PET) for cardiovascular applications. The protein layer was immobilized after an initial surface activation via a dopamine coating. The individual and synergetic effect of the dopamine deposition procedure and the substrate nature (pristine versus plasma-treated) was investigated via XPS, AFM, SEM and contact angle measurements. Dependent on the applied parameters, the post dopamine coating presented various surface roughnesses ranging between 96nm and 210nm. Subsequent gelatin immobilization mostly induced a smoothening effect, but the synergetic influence of the deposition protocol and plasma treatment resulted in different gelatin conformations. In addition, a comprehensive comparative study between chemically-modified (via dopamine) and physically-modified (physisorption) PET with gelatin was developed within the present study. All investigated samples were submitted to preliminary haemocompatibility tests, which clearly indicated the direct link between blood platelet behaviour and final protein arrangement.
Gold-dendrimer nanocomposites were obtained for the first time by a simple colloidal approach bas... more Gold-dendrimer nanocomposites were obtained for the first time by a simple colloidal approach based on the use of polyamidoamine dendrimers with succinamic acid terminal groups and dodecanediamine core. Spherical and highly crystalline nanoparticles with dimensions between 3 nm and 60 nm, and size-polydispersity depending on the synthesis conditions, have been generated. The influence of the stoichiometric ratio and the structural and architectural features of the dendrimers on the properties of the nanocomposites has been described. The self-assembling behaviour of these materials produces gold-dendrimer nanostructured porous networks with variable density, porosity, and composition. The investigations of the reaction systems, by TEM, at two postsynthesis moments, allowed to preliminary establish the control over the properties of the nanocomposite products. Furthermore, this study allowed better understanding of the mechanism of nanocomposite generation. Impressively, in the early...
ABSTRACT Polyesters represent a class of polymers comprised of backbone ester linkages offering o... more ABSTRACT Polyesters represent a class of polymers comprised of backbone ester linkages offering opportunities to tune the macromolecular properties according to the needs of specific applications. The polyesters developed to date have generated an enormous interest because of their applicability in the biomedical field. Although these are flexible materials in the sense that they can be chemically tuned to obtain the desired properties, one of the important parameters that has to be considered when designing the material for biomedical applications represents the biocompatibility. The present book chapter aims to review the recent advances for the most commonly studied polyester biomaterials. The first section of this chapter will focus on the synthesis strategies of polyesters as well as possible modification strategies. The second section of this chapter will highlight several polymer processing methods used to obtain scaffolds with different architectures for tissue engineering applications.
This work reports the synthesis of polymeric hybrids based on Casein and 2-hydroxyethyl methacryl... more This work reports the synthesis of polymeric hybrids based on Casein and 2-hydroxyethyl methacrylate polymers (PHEMA). Protein physical immobilization during the free-radical polymerization was performed. Two strategies were used to generate both films and cylinders. The homogeneity and the stability of the hybrids were assessed as well as their capacity to perform in vitro calcification when incubated in synthetic human plasma (SBF) for 14 days. Nucleation islets of calcium phosphate mineral in the form of nanometric nodules (20-30 nm) were observed on the Cas-rich domains. This study reports for the first time the synthesis of Cas-PHEMA materials and it tried to determine if these hybrids could cause a calcification under in vitro conditions.
Half of the annual human deaths worldwide are due to cardiovascular diseases [1]. Currently, synt... more Half of the annual human deaths worldwide are due to cardiovascular diseases [1]. Currently, synthetic grafts play a vital role in medicine, as implant demands exceed natural available sources and thus alternative solutions are needed. Poly(ethylene terephthalate) or PET is extensively used as a synthetic graft material on account of its excellent bulk properties (high mechanical and thermal properties) and chemical inertness. A major drawback is its poor surface properties that directly influence biological performance. Herein, we present a nature-inspired surface modification strategy suitable for fine-tuning surface properties of PET grafts. Materials & Methods. A two-step surface modification strategy was applied to PET (see Fig 1.). A dopamine-based coating procedure was used to facilitate the subsequent covalent immobilization of gelatin. In parallel, physisorbed surfaces were obtained by dip-coating. A surface characterization was performed using SCA, AFM and XPS, coupled wit...
The potential in vascular grafts of gelatin-modified poly(ethylene terephthalate) (PET) was shown... more The potential in vascular grafts of gelatin-modified poly(ethylene terephthalate) (PET) was shown herein via their coating stability, ability to promote endothelial cells (ECs) and smooth muscle cells (SMCs) and positive cyto- and endotoxicity assessments.
In vascular tissue engineering, great attention is paid to the immobilization of biomolecules ont... more In vascular tissue engineering, great attention is paid to the immobilization of biomolecules onto synthetic grafts to increase bio- and hemocompatibility-two critical milestones in the field. The surface modification field of poly(ethylene terephthalate) (PET), a well-known vascular-graft material, is matured and oversaturated. Nevertheless, most developed methods are laborious multistep procedures generally accompanied by coating instability or toxicity issues. Herein, a straightforward surface modification procedure is presented engineered to simultaneously promote surface endothelialization and anticoagulation properties via the covalent immobilization of gelatin through a photoactivated azide derivative. A complete physicochemical characterization and biological study including cytotoxicity and endotoxin testing are performed. In addition, biocompatibility toward small (diameter ≤ 6 mm) and/or large caliber (diameter ≥ 6 mm) vessels is assessed by micro- and macrovascular endot...
An aqueous-based bio-inspired approach was applied to chemically bind a bio compatible and cell-i... more An aqueous-based bio-inspired approach was applied to chemically bind a bio compatible and cell-interactive gelatin layer on poly(ethylene terephthalate) (PET) for cardiovascular applications. The protein layer was immobilized after an initial surface activation via a dopamine coating. The individual and synergetic effect of the dopamine deposition procedure and the substrate nature (pristine versus plasma-treated) was investigated via XPS, AFM, SEM and contact angle measurements. Dependent on the applied parameters, the post dopamine coating presented various surface roughnesses ranging between 96nm and 210nm. Subsequent gelatin immobilization mostly induced a smoothening effect, but the synergetic influence of the deposition protocol and plasma treatment resulted in different gelatin conformations. In addition, a comprehensive comparative study between chemically-modified (via dopamine) and physically-modified (physisorption) PET with gelatin was developed within the present study. All investigated samples were submitted to preliminary haemocompatibility tests, which clearly indicated the direct link between blood platelet behaviour and final protein arrangement.
Gold-dendrimer nanocomposites were obtained for the first time by a simple colloidal approach bas... more Gold-dendrimer nanocomposites were obtained for the first time by a simple colloidal approach based on the use of polyamidoamine dendrimers with succinamic acid terminal groups and dodecanediamine core. Spherical and highly crystalline nanoparticles with dimensions between 3 nm and 60 nm, and size-polydispersity depending on the synthesis conditions, have been generated. The influence of the stoichiometric ratio and the structural and architectural features of the dendrimers on the properties of the nanocomposites has been described. The self-assembling behaviour of these materials produces gold-dendrimer nanostructured porous networks with variable density, porosity, and composition. The investigations of the reaction systems, by TEM, at two postsynthesis moments, allowed to preliminary establish the control over the properties of the nanocomposite products. Furthermore, this study allowed better understanding of the mechanism of nanocomposite generation. Impressively, in the early...
ABSTRACT Polyesters represent a class of polymers comprised of backbone ester linkages offering o... more ABSTRACT Polyesters represent a class of polymers comprised of backbone ester linkages offering opportunities to tune the macromolecular properties according to the needs of specific applications. The polyesters developed to date have generated an enormous interest because of their applicability in the biomedical field. Although these are flexible materials in the sense that they can be chemically tuned to obtain the desired properties, one of the important parameters that has to be considered when designing the material for biomedical applications represents the biocompatibility. The present book chapter aims to review the recent advances for the most commonly studied polyester biomaterials. The first section of this chapter will focus on the synthesis strategies of polyesters as well as possible modification strategies. The second section of this chapter will highlight several polymer processing methods used to obtain scaffolds with different architectures for tissue engineering applications.
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Papers by Diana Giol