Bionanomaterials are promising materials produced from various biological elements, namely plants, bacteria, fungi, peptides, nucleic acids, etc. Bionanomaterials' utility in the biomedical field has gained them much attention as they are biologically synthesized and biocompatible. Owing to their miniature size, bionanomaterials exhibit extraordinary properties which help them gain potentialities in different domains like aerospace engineering, material science, pharmacology, biosensors, etc. Moreover, to study the properties of the synthesized bionanomaterials, various characterization techniques have been utilized. Hence, this chapter briefly describes the fundamentals of bionanomaterials along with their biomedical applications.
AbstractNanorods in nanotechnology called a specific type of morphology of nanoscale materials that their dimensions range is from 1 to 100 nm. Nanorods can be synthesized from metal or semi-conductive material with a surface to volume ratio of 3–5. One method of making nanorods is direct chemical method. Ligands compounds as a shape control agents cause growth the nanorods and create stretched and extended modes of them. In recent years, magnetic nanorods are one of the nanorods that have been raised in the field of nano medicine [Nath S, Kaittanis C, Ramachandran V, Dalal NS, Perez JM. Synthesis, magnetic characterization, and sensing applications of novel dextran-coated iron oxide nanorods. Chem Mater. 2009;21:1761–7.]. Superparamagnetic properties of magnetic nanorods causes to sensing be done with high accuracy. In addition, other applications of magnetic nanorods are in the field of separation and treatment [Hu B, Wang N, Han L, Chen ML, Wang JH. Magnetic nanohybrids loaded with bimetal core–shell–shell nanorods for bacteria capture, separation, and near-infrared photothermal treatment. Chemistry. 2015;21:6582–9.]. Therefore, in biomedical applications, the nanorods are used usually with biological molecules such as antibodies [Schrittwieser S, Pelaz B, Parak WJ, Lentijo-Mozo S, Soulantica K, Dieckhoff J, et al. Homogeneous protein analysis by magnetic core–shell nanorod probes. ACS Appl Mater Interfaces. 2016;8:8893–9.]. For this purpose, in the present work we will try to introduce magnetic nanorods and mention their different methods of synthesis and applications.
AbstractBiomaterials play a central role in modern strategies in regenerative medicine and tissue engineering to restore the structure and function of damaged or dysfunctional tissue and to direct cellular behavior. Both biologically derived and synthetic materials have been extensively explored in this context. However, most materials when implanted into living tissue initiate a host response. Modern implant design therefore aims to improve implant integration while avoiding chronic inflammation and foreign body reactions, and thus loss of the intended implant function. Directing these processes requires an in-depth understanding of the immunological processes that take place at the interface between biomaterials and the host tissue. The physicochemical properties of biomaterial surfaces (charge, charge density, hydrophilicity, functional molecular domains, etc.) are decisive, as are their stiffness, roughness and topography. This review outlines specific strategies, using polyelectrolyte multilayers to modulate the interactions between biomaterial surfaces and biological systems. The described coatings have the potential to control the adhesion of proteins, bacteria and mammalian cells. They can be used to decrease the risk of bacterial infections occurring after implantation and to achieve better contact between biological tissue and implants. In summary, these results are important for further development and modification of surfaces from different medical implants.
AbstractIn this study we investigate the impact of ligand presentation by various molecular spacers on integrin-based focal adhesion formation. Gold nanoparticles (AuNPs) arranged in hexagonal patterns were biofunctionalized with the same ligand head group, cyclic Arg-Gly-Asp [
AbstractSince late 1990s, polyetheretherketone (PEEK) has presented a promising polymeric alternative to metal implant components, particularly in orthopedic and traumatic applications. However, PEEK is biologically inert, which has constrained its potential applications. In this manner, enhancing the bioactivity of PEEK is a huge challenge that must be comprehended to completely understand the potential advantages. Up to now, two noteworthy methodologies are discussed to enhance the bioactivity of PEEK, including bulk and surface modification. Although the latter is extremely challenging due to the very high physical and chemical stability of the high performance polymer, there are some stated modification reactions in the literature, which will be collocated with in the literature-reported PEEK composites in the present article. We will furthermore add information on polymer-based drug delivery systems and the biofunctionalization of polymers in general and discuss their applicability for PEEK, as we estimate that these strategies will gain greater attention in the future. At the end of the article, our own research on the development of a PEEK-associated biodegradable drug-delivery system with potential application in dentistry or orthopedics will be highlighted.
AbstractThis work highlights the laser-based aqueous synthesis and processing of nanocomposites, composed of zinc or iron nanoparticles embedded in a
AbstractIn this study, surface modifications for the biodegradable polymers poly(ε-caprolactone) (PCL) and poly(3-hydroxybutyrate) [P(3HB)] were developed in order to improve their suitability as scaffold material for bioartificial vessel prostheses. The challenge of wet-chemical surface modifications is to avoid bulk adjustments resulting in undesired changes in mechanical properties of these polymers. Nevertheless subsequent immobilization and controlled release of potent angiogenic biomolecules like vascular endothelial growth factor (VEGF) from the polymer surface is required. In order to improve the biocompatibility of PCL and P(3HB), terminal hydroxyl groups on the surface of these polymers were generated via oxygen (O
AbstractCurrent implantable electrodes facilitate only a low cellular infiltration impairing the long-term integration into the host’s tissue. To accomplish a seamless electronic-tissue interface, conductive three-dimensional (3D) scaffolds were generated by carbonization of electro-spun fiber meshes. When introducing NaCl particles as porogens, tailored tissue-like electrodes were generated. Characterization of the porous 3D fiber electrodes demonstrated improved material and electrical characteristics compared to standard carbon fiber meshes or flat gold surfaces. The feasibility of the porous 3D electrodes was assessed by cell culture experiments, confirming the migration of cells into the electrode and the formation of contracting cardiomyocyte clusters. Finally, a complex cardiac co-culture system proved the integration of the tissue into the 3D electrode in long-term culture of 7 weeks. These results strengthen the development of tissue-like 3D scaffolds as alternative to two-dimensional (2D) electrodes.
AbstractIt is generally accepted that a micrometer scale roughness supports the osseointegration of titanium implants. While abrasive technologies can easily be employed to create a micro-topography on titanium surfaces, the preparation of rough ceramic surfaces is more challenging. Typically, abrasive treatments of yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) surfaces result in rather smooth topographies (R
Much effort is invested in the novel design and synthesis of biomaterials for the fabrication of biomedical applications as implants or nanoparticles with appropriate functionality, mechanical properties and durability. Depending on the application, requirements might differ considerably, ranging from high mechanical stress resistance to high transparency. These functions are generally governed by the bulk composition of the biomaterial. The biological response is in contrast largely controlled by the surface chemistry and structure. The rationale for surface modification of polymers is therefore straightforward: retaining the key physical properties of a biomaterial while modifying only the outermost surface to influence the biointeraction. Commonly observed interactions of any material with a biological system or system containing biomolecules cover adsorption or adhesion processes of proteins and bacteria or platelets as well as phagocytosis and fibrous encapsulation. Effective surface modification of biomaterials should mediate these interactions, for example, with the purpose of improved tissue-interface related-biocompatibility, that is especially important for modern implant design, which aim to improve implant integration while avoiding chronic inflammation and foreign body reactions, and thus loss of the intended implant function. Within the current issue, Hartmann and Krastev [1] outline specific strategies using polyelectrolyte multilayers to modulate these interactions between biomaterial surfaces and biological systems. Biofunctionalization is one particular form of surface modification involving the immobilization of biomolecules as proteins, peptides and polysaccharides or bioactive drugs with the same purpose. Various immobilization methods are available while the chosen strategy/design significantly defines the biological activity of the functionalized biomaterial. In this context, Spatz et al. [2] discuss the impact of spacer integration between biomaterial surface and the integrin-recognition motif cyclic RGD on the formation of integrin-based cellular adhesion. Furthermore, the immobilization strategy defines the short-term or long-term localization of the biomolecule on the biomaterials surface, which is explored using the example of the immobilization of the potent angiogenic vascular endothelial growth factor (VEGF) in order to improve the hemocompatibility and endothelialization of biodegradable polymer surfaces [3]. One more important field is the biofunctionalization of nanostructured materials and nanoparticles with possible biomedical application for imaging and quantifying of target molecules such as proteins in assays, cells and tissues. In this context, Walter et al. [4] give general insights into the principles and factors controlling the binding affinity of aptamers, as promising alternative binders that can substitute antibodies in various applications immobilized to nanostructured materials. The short review by Salehi [5] additionally summarizes current designs of different biofunctionalized nanoparticles as surface-enhanced Raman scattering substrates and highlights the improvement of particularly simple and gentle conjugation methods. One recently evolving field for surface functionalization can be found in dentistry. One focus in particular is the enhancement of the bioactivity of polyetheretherketone (PEEK) that presents a promising polymeric alternative to metal implant components. A review of PEEK modification reactions are collocated with general information on polymer-based drug delivery systems as well as the biofunctionalization of polymers and with a discussion of their applicability for PEEK in the article by Harting et al. [6]. Freifrau von Maltzahn et al. [7] in contrast highlights the evaluation of the antibacterial effect of a drug releasing poly(3-hydroxybutyrate) [P(3HB)] implant coating in comparison to pure titanium on Aggregatibacter actinomycetemcomitans as a model periodontopathogen to prevent biofilm formation on dental implant surfaces. A further modification possibility is the alteration of surface roughness of dental implant surfaces. Grohmann et al. [8] report results on in vitro and in vivo experiments of rough yttria-stabilized tetragonal zirconia polycrystal materials revealing a cytocompatibility and a bone-implant contact that is very comparable to titanium as a reference material. The editors are aware that this issue can only highlight some of the multiple aspects in biofunctionalization. We hope that our selection of the articles included will stimulate your work towards innovative applications and you will enjoy this issue!
Abstract Background The aim of the study was to evaluate the antibacterial effect of a drug releasing poly (3-hydroxybutyrate) (P(3HB)) implant coating in comparison to pure titanium on Aggregatibacter actinomycetemcomitans as a model periodontopathogen to prevent biofilm formation on implant surfaces. Methods Titanium discs were coated with P(3HB) containing 5% (w) and 10% (w) of metronidazole, either with and without a P(3HB) topcoat. The biofilm formation was evaluated after 1, 4 and 9 days in a dynamic flow chamber system. Microbial adherence was quantified by determination of bacterial surface coverage. Results The evaluated formulations of P(3HB)/metronidazole showed an antibacterial effect especially in the first 24 h. Prolonged incubation for 9 days showed reduced bacterial adhesion only on polymer coatings loaded with 10% (w) of metronidazole both with and without topcoat. Conclusions The evaluated coating formulations can provide protection from an Aggregatibacter actinomycetemcomitans in vitro biofilm formation for the time period which was evaluated.
