29 research outputs found
Nanoparticle delivery systems in the treatment of diabetes complications
Diabetes mellitus, an incurable metabolic disease, is characterized by changes in the homeostasis of blood sugar levels, being the subcutaneous injection of insulin the first line treatment. This administration route is however associated with limited patients compliance, due to the risk of pain, discomfort and local infection. Nanoparticles have been proposed as insulin carriers to make possible the administration of the peptide via friendlier pathways without the need of injection, i.e., via oral or nasal routes. Nanoparticles stand for particles in the nanometer range that can be obtained from different materials (e.g., polysaccharides, synthetic polymers, lipid) and are commonly used with the aim to improve the physicochemical stability of the loaded drug and thereby its bioavailability. This review discusses the use of different types of nanoparticles (e.g., polymeric and lipid nanoparticles, liposomes, dendrimers, niosomes, micelles, nanoemulsions and also drug nanosuspensions) for improved delivery of different oral hypoglycemic agents in comparison to conventional therapies.The authors acknowledge the financial support received from Portuguese Science and Technology Foundation (FCT/MCT) and from European Funds (PRODER/COMPETE) under the project reference M-ERA-NET/0004/2015-PAIRED, co-financed by FEDER, under the Partnership Agreement PT2020. The authors also acknowledge the support of the research project: “Nutraceutica come supporto nutrizionale nel paziente oncologico”, CUP: B83D18000140007.info:eu-repo/semantics/publishedVersio
Engineering nanoparticles for targeting rheumatoid arthritis: Past, present, and future trends
Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by synovial joint inflammation and cartilage and bone tissue destruction. Although there exist some treatment strategies for RA, they are not completely safe and effective. Therefore, it is important to develop and test new drugs for RA that specifically target inflamed/swollen joints and simultaneously attenuate other possible damages to healthy tissues. Nanotechnology can be a good alternative to consider when envisioning precise medication for treating RA. Through the use of nanoparticles, it is possible to increase bioavailability and bioactivity of therapeutics and enable selective targeting to damaged joints. Herein, recent studies using nanoparticles for the treatment of RA, namely with liposomes, polymeric nanoparticles, dendrimers, and metallic nanoparticles, have been reviewed. These therapeutic strategies have shown great promise in improving the treatment over that by traditional drugs. The results of these studies confirm that feasibility of the use of nanoparticles is mainly due to their biocompatibility, low toxicity, controlled release, and selective drug delivery to inflamed tissues in animal RA models. Therefore, it is possible to claim that nanotechnology will, in the near future, play a crucial role in advanced treatments and patient-specific therapies for human diseases such as RA.Financial support under the ARTICULATE project (No. QREN-13/SI/2011-23189). This study was also funded by the Portuguese Foundation for Science and Technology (FCT) project OsteoCart (No. PTDC/CTM-BPC/115977/2009), as well as the European Union’s FP7 Programme under grant
agreement no REGPOT-CT2012-316331-POLARIS. The FCT distinction attributed to J. M. O. under the
Investigator FCT program (No. IF/00423/2012) is
also greatly acknowledged. C. G. also wished to
acknowledge FCT for supporting her research (No.
SFRH/BPD/94277/2013)info:eu-repo/semantics/publishedVersio
Ba<SUB>3</SUB>ZnTa<SUB>2−x</SUB>Nb<SUB>x</SUB>O<SUB>9</SUB> and Ba<SUB>3</SUB>MgTa<SUB>2−x</SUB>Nb<SUB>x</SUB>O<SUB>9</SUB> (0≤x ≤1): synthesis, structure and dielectric properties
Oxides belonging to the families Ba3ZnTa2−xNbxO9 and Ba3MgTa2−xNbxO9 were synthesized by the solid state reaction route. Sintering temperatures of 1300°C led to oxides with disordered (cubic) perovskite structure. However, on sintering at 1425°C hexagonally ordered structures were obtained for Ba3MgTa2−xNbxO9 over the entire range (0≤x≤1) of composition, while for Ba3ZnTa2−xNbxO9 the ordered structure exists in a limited range (0≤x≤0.5). The dielectric constant is close to 30 for the Ba3ZnTa2−xNbxO9 family of oxides while the Mg analogues have lower dielectric constant of ~18 in the range 50 Hz to 500 kHz. At microwave frequencies (5-7 GHz) dielectric constant increases with increase in niobium concentration (22-26) for Ba3ZnTa2−xNbxO9; for Ba3MgTa2−xNbxO9 it varies between 12 and 14. The "Zn" compounds have much higher quality factors and lower temperature coefficient of resonant frequency compared to the "Mg" analogues
Synthesis and microwave dielectric properties of Sr<SUB>3</SUB>Zn<SUB>1−x</SUB>Mg<SUB>x</SUB>Nb<SUB>2</SUB>O<SUB>9</SUB> phases
Oxides of the type, Sr3Zn1−xMgxNb2O9 (0≤x≤1) have been obtained by the ceramic method. These oxides crystallize in the hexagonal cell corresponding to ordered triple perovskites. Sintered disks show nearly frequency-independent dielectric constant for all the compositions. Compositions sintered at 1425°C yield dielectric constant of 20-22 at ~6 GHz, with quality factor ranging from 1300 to 1500. Sr3Zn0.5Mg0.5Nb2O9 shows a very low temperature coefficient of resonant frequency (Tf) of +4 ppm/°C
Through the Eyes of Creators: Observing Artificial Molecular Motors : ACS Nanoscience Au
Inspired by molecular motors in biology, there hasbeen significant progress in building artificial molecular motors, usinga number of quite distinct approaches. As the constructs become moresophisticated, there is also an increasing need to directly observe themotion of artificial motors at the nanoscale and to characterize theirperformance. Here, we review the most used methods that tacklethose tasks. We aim to help experimentalists with an overview of theavailable tools used for different types of synthetic motors and tochoose the method most suited for the size of a motor and the desiredmeasurements, such as the generated force or distances in the movingsystem. Furthermore, for many envisioned applications of syntheticmotors, it will be a requirement to guide and control directed motions.We therefore also provide a perspective on how motors can be observed on structures that allow for directional guidance, such asnanowires and microchannels. Thus, this Review facilitates the future research on synthetic molecular motors, where observations ata single-motor level and a detailed characterization of motion will promote applications
Motility of an autonomous protein-based artificial motor that operates via a burnt-bridge principle
Abstract Inspired by biology, great progress has been made in creating artificial molecular motors. However, the dream of harnessing proteins – the building blocks selected by nature – to design autonomous motors has so far remained elusive. Here we report the synthesis and characterization of the Lawnmower, an autonomous, protein-based artificial molecular motor comprised of a spherical hub decorated with proteases. Its “burnt-bridge” motion is directed by cleavage of a peptide lawn, promoting motion towards unvisited substrate. We find that Lawnmowers exhibit directional motion with average speeds of up to 80 nm/s, comparable to biological motors. By selectively patterning the peptide lawn on microfabricated tracks, we furthermore show that the Lawnmower is capable of track-guided motion. Our work opens an avenue towards nanotechnology applications of artificial protein motors
Adverse drug reaction profile of cisplatin-based chemotherapy regimen in a tertiary care hospital in India: An evaluative study
Aims : This prospective study was designed to monitor and analyze the
pattern of occurrence of adverse drug reactions (ADRs) to
cisplatin-based chemotherapy regimen in the cancer ward of a tertiary
care hospital. Materials and Methods : Cancer patients who received
cisplatin-based cancer chemotherapy were monitored for adverse
reactions. The collected reports were analyzed for demographic and drug
details, causality, preventability and severity of adverse effects.
Causality was assessed by the World Health Organization (WHO) causality
assessment scale and Naranjo′s Algorithm. Preventability and
severity of ADRs were assessed by modified Schumock and Thornton scale,
modified Hartwig and Siegel scale respectively. Results : Among 51
patients, 48 developed ADRs to cisplatin chemotherapy. The reactions
observed were nausea, alopecia, anorexia, vomiting, taste alteration,
diarrhea, constipation, tinnitus, and hypocalcaemia. The WHO causality
assessment scale indicated 69% "possible" and 31% "probable" but no
"certain" reactions. Naranjo′s Algorithm showed 62% "probable"
and 38% "possible" reactions. Most of the reactions belonged to the
category of "not preventable". Reactions like nausea and vomiting
belonged to the category of "definitely preventable". Modified Hartwig
and Siegel scale of severity assessment showed that most of the
reactions were of "mild level 1" severity except for vomiting, diarrhea
and hypocalcaemia, which were of "moderate level 3" severity.
Conclusion : Cisplatin-based chemotherapy has a high potential to cause
adverse effects. Most of the reactions were of milder nature but not
preventable. The common adverse effects such as nausea and vomiting
were preventable, but reactions like hypersensitivity reactions and
anaphylaxis were not predictable