1,721,051 research outputs found
A New One-Pot Way to Prepare Enzyme-Containing Coordination Polymers by Sonochemistry
No full textEnzyme-containing Coordination Polymers (CPs) were prepared by a one-pot sonochemical method, mixing Glucose Oxidase (GOx) enzyme, 4,4'-bipyridine as spacer ligand, and chloride zinc salt. The reaction took place in a very short time (a few minutes) with a minimum use of solvents compared to conventional methods. The obtained composite material, named GOx-[Zn(4,4'-bipy)Cl2]∞, resulted from embedding the GOx molecules into uniformly sized [Zn(4,4'-bipy)Cl2] nanocrystals. The structural and thermal characterization, confirmed that the adopted strategy allows the preparation of hybrid bio-nanomaterials in a very fast, facile and eco-friendly method, by simply synthesising the [Zn(4,4'-bipy)Cl2] nanocrystals in the presence of the enzyme
Effect of Manual Grinding on Diclofenac Acid Nanocrystals: A Chemico-Physical Investigation
No full textX-ray Powder Diffraction, Fourier Transform Infrared Spectroscopy and Differential Scanning Calorimeter were used to study the effect of the manual grinding in an agate mortar of the diclofenac acid polymorphs HD1 and HD2. In particular, we have tried to highlight how the HD2 form is more sensitive than the HD1 to the grinding process to achieve a nanometric crystal size. HD1 shows no change, while in the case of the HD2, changes in the molecular conformation and the formation of a new metastable form of the polymorph are observed after grinding
ANTIBACTERIAL COATING
No full textThe invention relates to a coating with antibacterial properties. In particular, the invention relates to a composition for obtaining an antibacterial coating obtained with the sol-gel technique, to the relative preparation method and to the articles which present said coating. The antibacterial coating is obtained with the sol-gel method starting from a mixture comprising tetraethyl-orthosilicate and an ionic liquid in a molar ratio between 8 and 100
Alternative Silica Sources in the Synthesis of Ordered Mesoporous Silica
No full textIn this work, the influence of the use of alternative inexpensive silica sources on the structural, morphological and textural properties of MCM-41 like mesoporous materials to be used for biomedical applications has been investigated. The Liquid Crystal Template Method has been used to prepare the ordered mesoporous structured materials according to a novel composition starting from fumed silica or granular silica gel as alternative silica sources. The obtained materials have been characterized by X-ray Powder Diffraction, Transmission and Scanning Electron Microscopy, and nitrogen sorption, which showed for both samples the formation of the ordered hexagonal pore arrangement typical of a MCM-41 material. However, when using fumed silica, higher long-range hexagonal pore ordering as well as higher surface area have been obtained (1030 vs. 763 m2/g). For comparison, the features of a commercial silica mesostructured MCM-41 type have been investigated as well. Again, the silica fumed based sample has showed higher long-range hexagonal pore ordering, higher surface area and wall thickness. Preliminary stability studies on the fumed silica based material showed a decrease in the pore ordering at the end of the third year after the synthesis
A Special Section on Recent Advances in Nanomaterials for Biomedical Applications
No full textA Special Issue on Recent Advances in Nanomaterials for Biomedical Applications
During recent decades, the development of nanostructures has gained considerable attention in a vast range of scientific fields including engineering, physics, chemistry, biology and medicine. In particular, it is worldwide recognized by scientists that nanomaterials are bound to have a strong impact on the biomedical sector, due to their potential use as diagnostics and therapeutics, which can revolutionize current medicine approaches. Investigations on nanomaterials for biomedical applications consist in the design, preparation, characterization and testing of nanostructured materials, made either of inorganic or organic components as well as of hybrid organic–inorganic materials, properly tailored and combined into single nano-objects. They represent a versatile platform for new therapeutic strategies such as drug delivery, imaging and tissue repair. Moreover, their combination with biologic(al) medical products (genes, proteins and enzymes) could open new horizons to healthcare in the coming years. This Special Issue of the Journal of Nanoscience and Nanotechnology focuses on the recent advances in the development and application of nanomaterials for biomedicine. It aims to provide a survey of the current topics and the major development lines in this rapidly growing research area. Five Reviews open the Special Issue, giving a general overview on the recent achievements in the preparation of different types of nanoparticles and nanocomposites for the applications as diagnostics and/or therapeutics. Then, a selection of original manuscripts in the form of fourteen Full Papers and six Communications, is dedicated to the last advancement and future perspectives in the synthesis, characterization and preliminary validation of the last-generation inorganic (ordered mesoporous silica, metal oxide and amorphous nanoparticles), organic (drug based-nanocrystals, liposomes and proniosomes), and hybrid (coordination polymers and multifunctionalized nanoparticles) materials. The Editors would like to thank the authors for their excellent contributions and all Reviewers for their great efforts in assisting us during the reviewing process of the manuscripts, both contributing to the high scientific level of this Special Issue. Finally, a special thanks to the Editor-in- Chief Dr. Hari Singh Nalwa and the European Editor Dr. Davide Barreca, who gave us the opportunity to realize the Special Issue, and to the JNN staff for their technical support.
We hope the readers will enjoy this Special Issue.
Guest Editors Guido Ennas Alessandra Scano Chiara Sinico Francesco La
Photodynamic therapy for the successful management of cyclosporine-related gum hypertrophy: A novel therapeutic option
Full text linkBACKGROUND: Drug-induced gingival overgrowth is associated with the intake of three classes of drugs: anticonvulsants, immunosuppressants, and calcium channel blockers. It is clinically characterized by hyperplasia of the gingival connective tissue which appears edematous, bloody, and purplish-red in color. In more severe cases, drug-induced gingival hyperplasia negatively affects the patient’s quality of life, making it difficult to eat and practice good oral hygiene. Drug-induced gingival overgrowth therapy is controversial and, in fact, no studies in the literature highlight a well-defined therapeutic protocol. The therapies that are described provide primarily for non-surgical periodontal treatment and second-line surgical treatment. The aim of this work is to highlight a case of drug-induced gingival hyperplasia which was completely resolved thanks to photodynamic therapy which is completely free from side effects. DESIGN AND METHODS: Photodynamic therapy was performed on an 18 year-old female patient with LEDs at a power of 450–470 nm and 5500 mW/cm(2) + 7500 mW/cm(2), combined with a Curcuma longa-based photosensitizer. A single session was performed, with applications of approximately 30 s for each interdental papilla. RESULTS: The patient improved markedly after only one cycle of PDT. There was an absence of clinically detectable inflammation, edema, and rubor of the involved dental papillae. At the 4, 6, and 12 week follow-ups there were no recurrences. CONCLUSIONS: This case report highlights the first case of drug-induced gingival hypertrophy entirely treated with photodynamic therapy to be described in the literature. Therefore, although it is only a case report, this therapy which is free from side effects should be investigated as an alternative to current therapies
Liposomes for (trans)dermal delivery of tretinoin: influence of drug concentration and vesicle composition
No full textThe influence of drug concentration and vesicel composition on the (trans)dermal delivery of tretinoin (TRA) was studied.To this purpose tretinoin was incorporated at different concentrations in unilamellar liposomes (UVs) prepared by sonication using phospholipids with different transition temperature (T-c): hydrogenated soy phosphatidylcholine (Tc = 51 degrees C) or dipalmitoylphosphatidylcholine (Tc = 41 degrees C). Vesicle dispersions were characterized in terms of morphology size distribution and incorporation efficiency by using respectively optical and polarized light microscopy, transmission electron mciroscopy, dynamic laser light scattering, and HPLC. The effect of the vesicular incorporation of tretinoin at different molar ratios was investigated by zeta potential measurements and differential scanning calorimetry analysis. These analyses inidcated that tretinoin principally interacts with the lipid groups until bilayer saturation. At higher concentration the ionized drug interacts with the polar head. Interactions between new-born pig skin and vesicle containing different amount of tretinoion were evaluated in vitro using Franz cells. The results obtained confirmed that liposomes saturated with TRA (molar fraction = 0.3) are capable of significantly promoting drug accumulation in the pig skin and that (trans)cutaneous delivery is strongly dependent on vesicular stability on the skin
Are dentists aware of post-traumatic trigeminal neuropathic pain? A web-based epidemiological survey
Full text linkBackground: Post-traumatic trigeminal neuropathic pain represents neuropathic pain in the distribution of the trigeminal nerve caused by trauma to the trigeminal nerve. Dental traumatic interventions, such as root-canal therapy and extractions, are reported to precede, in some cases, the onset of the disease. The current study aims to investigate how much dentists are trained to recognize, treat or properly address patients suffering from Post-traumatic trigeminal neuropathic pain. Methods: Data were collected from a large sample of Italian dentists in 2021. The setting of this study relates to an epidemiological survey conducted on the web. Google Forms, a product of Google Inc., was used as the operating system. An online questionnaire was sent to each participant, and the degree of knowledge of the disease along with the direct experience of having encountered it was investigated through specific multiple-choice questions. Results: 634 dentists participated in the survey. 29% of participants declared to be unaware of the existence of Post-traumatic trigeminal neuropathic pain. 70% of dentists reported to have had patients suspicious of such pain in their clinical activity, following endodontic treatment (60%), tooth extraction (43%), spontaneously (37%) or other dental therapies (21%). When encountered, only in one out of three cases were patients sent to a pain specialist, and in most cases dentists performed irreversible therapies the site of the pain. Conclusions: This study evidences a major public health problem, such as the incapability of clinicians to perform a correct diagnosis and management of Post-traumatic trigeminal neuropathic pain. Such a lack of knowledge costs the patients mistaken and irreversible surgical therapies in many cases, and resulting delays in receiving proper diagnosis and management that could affect the success of the treatment. Furthermore, the unawareness had high socioeconomic costs for both the healthcare system and the patients due to the disability. Clinical trial registration: NP/2021/5460, Institutional Review Boards of the University of Cagliari, Italy
Mechanochemical reactivity of square-planar nickel complexes and pyridyl-based spacers for the solid-state preparation of coordination polymers: the case of nickel diethyldithiophosphate and 4,4′-bipyridine
No full textThe mechanochemical synthesis of a coordination polymer from a preformed metal coordination complex and a pyridyl-based spacer has been successfully performed. The coordination polymer (1·L)∞ was obtained rapidly from the reaction of the neutral square-planar complex [{(EtO)2PS2}2Ni] (1) and 4,4′-bipyridine (L) at room temperature through two different mechanochemical approaches (neat grinding and liquid-assisted grinding). The products were characterized by X-ray powder diffraction, IR spectroscopy, scanning electron microscopy, thermogravimetry and differential scanning calorimetry techniques. In parallel (1·L)∞ was prepared by conventional solvent-based methods, and the X-ray crystal structure of the polymer, obtained as single crystals, was compared with that from the mechanochemical preparation
High Energy Ball Milling and Liquid Crystal Template Method: A Successful Combination for the Preparation of Magnetic Nano-Platforms
No full textIn this study, we present the preparation of superparamagnetic ordered mesoporous silica (SOMS) for biomedical applications by the combination of high energy ball milling (HEBM) and the liquid crystal template method (LCT) to produce a material comprised of room temperature superparamagnetic Fe3O4 nanoparticles in a MCM-41 like mesostructured silica. In a typical synthesis, a mixture of Fe2O3 and silica was sealed in a stainless-steel vial with steel balls. Ball milling experiments were performed in a vibratory mill apparatus. The milling process produced nanocomposites with an average size ranging from ∼100-200 nm, where the Fe3O4 nanoparticles (4.8 nm size) are homogeneously dispersed into the amorphous SiO2 matrix. The obtained nanocomposite has been used for the preparation of the SOMS through the LCT method. Structural, morphological and textural characterization were performed using X-ray powder diffraction, transmission electron microscopy and nitrogen sorption analysis. Field dependence of magnetization was investigated and showed superparamagnetic behaviour at 300 K with a value of saturation magnetization (Ms) that is of interest for biomedical applications
- …
