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[Display omitted] Periodontitis is a chronic infectious and inflammatory disease of periodontal tissues estimated to affect 70–80 % of all adults. At the same time, periodontium, the site of periodontal pathologies, is an extraordinarily complex plexus of soft and hard tissues, the regeneration of which using even the most advanced forms of tissue engineering continues to be a challenge. Nanotechnologies, meanwhile, have provided exquisite tools for producing biomaterials and pharmaceutical formulations capable of elevating the efficacies of standard pharmacotherapies and surgical approaches to whole new levels. A bibliographic analysis provided here demonstrates a continuously increasing research output of studies on the use of nanotechnologies in the management of periodontal disease, even when they are normalized to the total output of studies on periodontitis. The great majority of biomaterials used to tackle periodontitis, including those that pioneered this interesting field, have been polymeric. In this article, a chronological review of polymeric nanotechnologies for the treatment of periodontitis is provided, focusing on the major conceptual innovations since the late 1990s, when the first nanostructures for the treatment of periodontal diseases were fabricated. In the opening sections, the etiology and pathogenesis of periodontitis and the anatomical and histological characteristics of the periodontium are being described, along with the general clinical manifestations of the disease and the standard means of its therapy. The most prospective chemistries in the design of polymers for these applications are also elaborated. It is concluded that the amount of innovation in this field is on the rise, despite the fact that most studies are focused on the refinement of already established paradigms in tissue engineering rather than on the development of revolutionary new concepts. [ABSTRACT FROM AUTHOR]

[Display omitted] Periodontitis is a chronic infectious and inflammatory disease of periodontal tissues estimated to affect 70–80 % of all adults. At the same time, periodontium, the site of periodontal pathologies, is an extraordinarily complex plexus of soft and hard tissues, the regeneration of which using even the most advanced forms of tissue engineering continues to be a challenge. Nanotechnologies, meanwhile, have provided exquisite tools for producing biomaterials and pharmaceutical formulations capable of elevating the efficacies of standard pharmacotherapies and surgical approaches to whole new levels. A bibliographic analysis provided here demonstrates a continuously increasing research output of studies on the use of nanotechnologies in the management of periodontal disease, even when they are normalized to the total output of studies on periodontitis. The great majority of biomaterials used to tackle periodontitis, including those that pioneered this interesting field, have been polymeric. In this article, a chronological review of polymeric nanotechnologies for the treatment of periodontitis is provided, focusing on the major conceptual innovations since the late 1990s, when the first nanostructures for the treatment of periodontal diseases were fabricated. In the opening sections, the etiology and pathogenesis of periodontitis and the anatomical and histological characteristics of the periodontium are being described, along with the general clinical manifestations of the disease and the standard means of its therapy. The most prospective chemistries in the design of polymers for these applications are also elaborated. It is concluded that the amount of innovation in this field is on the rise, despite the fact that most studies are focused on the refinement of already established paradigms in tissue engineering rather than on the development of revolutionary new concepts. [ABSTRACT FROM AUTHOR]

Colloidal stability and the regularity of the release kinetics benefit from the high circularity and the narrow size dispersion of polymeric particles as drug delivery carriers. A method for obtaining such particles composed of poly(lactide- co -glycolide) (PLGA), averaging at 1.0 ± 0.3 µm in size, is reported here, along with the analysis of the effects of different synthesis parameters on their morphological characteristics. As in agreement with the classical nucleation theory, the particle size and the degree of cohesion were inversely proportional to supersaturation. Consequently, the optimal conditions for the precipitation of small and narrowly dispersed particles involved an abrupt elevation of supersaturation. Owing to the high colloidal stability of the particles, centrifugation exhibited a counterintuitive effect on them, refining their morphological features and promoting their individuation. Polyvinyl alcohol (PVA) was used as a steric repulsion additive and its effect on the stability of PLGA spheres was concentration-dependent, with the particles aggregating, partially coalescing and losing their distinct features both with no PVA in the system and at PVA concentrations higher than the optimal. At its narrowest, the particle size distribution was bimodal, exhibiting the average circularity of 0.997 ± 0.003 and the average roundness of 0.913 ± 0.054. PLGA spheres were loaded with an inhibitor of EhCP4, a cysteine protease from E. histolytica , a parasite causing amoebic dysentery in the tropical and developing world. The burst release of the drug at early time points was followed by a zero-order release period, yielding a biphasic profile that can be of benefit in the delivery of anti-infective agents. The release profile fitted poorly with the Hixson-Crowell kinetic model and excellently with the Higuchi and the Korsmeyer-Peppas ones, indicating that the release is conditioned by diffusion rather than by the degradation of the polymer. The release and the erosion proceeded independently from one another, suggesting that the pore formation, water penetration and swelling are the primary driving forces for the release of the drug. [ABSTRACT FROM AUTHOR]

Composite structures are at the frontier of materials science and engineering and polymeric/ceramic composites present one of their most prospective subsets. Prior studies have shown both improvements and deteriorations of properties of polymers upon the addition of ceramic phases to them, but not many studies have dealt with the direct comparison of chemically distinct inorganic additives. The goal of this study was to compare the properties of ε-polycaprolactone (PCL) thin films supplemented with alumina, graphene, carbonated hydroxyapatite or titania particles, individually, in identical amounts (12 wt%). The composite films were analyzed for their phase composition, grain size, morphology, surface roughness, porosity, cell response, mechanical properties and electrochemical performance. Each additive imparted one or more physical or biological properties onto PCL better than others. Thus, alumina increased the microhardness of the films better than any other additive, with the resulting values exceeding 10 MPa. It also led to the formation of a composite with the least porosity and the greatest stability to degradation in simulated body fluid based on open circuit potential (OCP) measurements and electrochemical impedance spectroscopy (EIS). Titania made the surface of PCL roughest, which in combination with its high porosity explained why it was the most conducive to the growth of human fibroblasts, alongside being most prone to degradation in wet, corrosive environments and having the highest Poisson's ratio. Graphene, in contrast, made the surface of PCL smoothest and the bulk structure most porous, but also most conductive, with the OCP of −37 mV. The OCP of PCL supplemented with carbonated hydroxyapatite had the highest OCP of −134 mV and also the highest mechanical moduli, including the longitudinal (781 MPa), the shear (106 MPa), the bulk (639 MPa), and the elastic (300 MPa). The only benefit of the deposition of multilayered PCL films supplemented with all four inorganic additives was to enable a relatively high resistance to degradation. This study demonstrates that the properties of thin PCL films could be effectively optimized through the simple choice of appropriate inorganic additives dispersed in them. There is no single additive that proves ideal for improving all the properties of interest in PCL thin films, but their choice should be adjusted to the actual application. One such method of compositional optimization could prove crucial in the effort to develop biocomposites for superior performance in tissue engineering applications. [ABSTRACT FROM AUTHOR]

The necessity for finding a compromise between mechanical and biological properties of biomaterials spurs the investigation of the new methods to control and optimize scaffold processing for tissue engineering applications. A scaffold composed of ε-polycaprolactone fibers reinforced with carbonated hydroxyapatite (CHAP) dually doped with selenite oxyanions (Se) and cationic gold (Au) was synthesized using the electrospinning technique and studied at different contents of Au. Despite the fact that the amount of the Au dopant was relatively low, variations to it induced significant microstructural changes, affecting the cell response and mechanical properties in return. Au nanoparticles segregated as a separate, ternary phase at the highest Au content, corresponding to x = 0.8 in the Au x Ca 10−1.5x (PO 4) 5.8 (SeO 2) 0.2−x (CO 3) x (OH) 2 stoichiometric formula of Au/Se-CHAP. Their appearance coincided with a rapid degeneration in the density and adhesion of osteoblastic cells grown on the scaffolds. In spite of this adverse effect, the cell spreading and proliferation improved with increasing the amount of the Au dopant in the Au/Se-CHAP particles of the scaffold in the x = 0.0–0.6 range, suggesting that the biological effects of Au in the ionic and in the nanoparticulate form on the implant integration process may be diametrically opposite. The addition of Au had a dramatic effect on some mechanical properties, such as toughness and strain at break, which were both reduced twice upon the introduction of Au into Se-CHAP at the lowest amount (x = 0.2) compared to the Au-free composite. The significant variation of physical and biological properties of these composite scaffolds with trace changes in the content of the Au dopant inside the ceramic filler particles is promising, as it provides a new, relatively subtle avenue for tailoring the properties of tissue engineering scaffolds for their intended biomedical applications. [ABSTRACT FROM AUTHOR]