Search results for " Controlled release"
showing 10 items of 13 documents
Selective, Highly Sensitive, and Rapid Detection of Genomic DNA by Using Gated Materials:MycoplasmaDetection
2013
The coupling of gated-indicator delivery with highly specific biochemical recognition is an innovative strategy for the detection of DNA sequences, able to compete with classical methods which need PCR amplification, in important areas such as point-of-care diagnostics or detection of specific biological contaminations with pathogens. Such comparatively simple and cheap yet highly selective and sensitive assays hold promise for use in less-developed areas of the world.
Halloysite Nanotubes: Controlled Access and Release by Smart Gates
2017
© 2017 by the authors. Licensee MDPI, Basel, Switzerland. Hollow halloysite nanotubes have been used as nanocontainers for loading and for the triggered release of calcium hydroxide for paper preservation. A strategy for placing end-stoppers into the tubular nanocontainer is proposed and the sustained release from the cavity is reported. The incorporation of Ca(OH) 2 into the nanotube lumen, as demonstrated using transmission electron microscopy (TEM) imaging and Energy Dispersive X-ray (EDX) mapping, retards the carbonatation, delaying the reaction with CO 2 gas. This effect can be further controlled by placing the end-stoppers. The obtained material is tested for paper deacidification. We…
Green composites for fertilizer controlled release produced by compression molding and FDM
2023
Excessive fertilization causes ecological problems due to leaching issues. To solve this problem and promote agriculture sustainability an innovative green composite for controlled release fertilizers was produced by adding NPK fertilizer flour to a biodegradable polymer with or without Opuntia Ficus Indica (OFI) particles. Six formulations were produced and employed for the fabrication of devices both for compression molding (CM) and fused deposition modeling (FDM). Both fillers displayed a good dispersion in the composites, excellent adhesion with the polymeric matrix and effectively acted as reinforcement. The decrease of NPK release rate (up to 30 days) was achieved using whole composit…
Enzyme-Responsive Intracellular Controlled Release Using Nanometric Silica Mesoporous Supports Capped with "Saccharides"
2010
The synthesis of new capped silica mesoporous nanoparticles for on-command delivery applications is described. The gate-like functional hybrid systems consisted of nanoscopic MCM-41-based materials functionalized on the pore outlets with different “saccharide” derivatives and a dye contained in the mesopores. A series of hydrolyzed starch products as saccharides were selected. The mesoporous silica nanoparticles S1, S2, and S3 containing the grafted starch derivatives Glucidex 47, Gludicex 39, and Glucidex 29 were synthesized. Additionally, for comparative purposes solid S4 containing lactose was prepared. Delivery studies in pure water in the presence of pancreatin or -D-galactosidase were…
Pt(II) complex @mesoporous silica: preparation, characterization and study of release
2016
Cisplatin analogs, having cytotoxic activity higher than that exerted by cisplatin, have recently triggered considerable interest by the community. The cis-[PtCl2(DMSO)HL]·2DMSO, where HL = 7-amino-2-(methylthio)[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylic acid, has shown a potent cytotoxic activity on HepG2 hepatocarcinoma cells, while under identical conditions, it did not affect normal immortalized human liver cells (Chang). In this work, the above complex has been incorporated into MCM41 mesoporous silica, pure and functionalized with amino group, which is considered one of the best host for a drug delivery system for carrying high dosages of a variety of drugs in their mesopores. Sinc…
Glucose-triggered release using enzyme-gated mesoporous silica nanoparticles.
2013
[EN] A new gated nanodevice design able to control cargo delivery using glucose as a trigger and cyclodextrin-modified glucose oxidase as a capping agent is reported.
Formulation of Mesoporous Silica Nanoparticles for Controlled Release of Antimicrobials for Stone Preventive Conservation
2020
The biotic deterioration of artifacts of archaeological and artistic interest mostly relies on the action of microorganisms capable of thriving under the most disparate environmental conditions. Thus, to attenuate biodeterioration phenomena, biocides can be used by the restorers to prevent or slow down the microbial growth. However, several factors such as biocide half-life, its wash-out because of environmental conditions, and its limited time of action make necessary its application repeatedly, leading to negative economic implications. Sound and successful treatments are represented by controlled release systems (CRSs) based on porous materials. Here, we report on the design and developm…
Single cigar-shaped nanopores functionalized with amphoteric amino acid chains: experimental and theoretical characterization.
2012
We present an experimental and theoretical characterization of single cigar-shaped nanopores with pH-responsive carboxylic acid and lysine chains functionalized on the pore surface. The nanopore characterization includes (i) optical images of the nanostructure obtained by FESEM; (ii) different chemical procedures for the nanopore preparation (etching time and functionalizations; pH and electrolyte concentration of the external solution) allowing externally tunable nanopore responses monitored by the current-voltage (I-V) curves; and (iii) transport simulations obtained with a multilayer nanopore model. We show that a single, approximately symmetric nanopore can be operated as a reconfigurab…
Selective adsorption of oppositely charged PNIPAAM on halloysite surfaces: a route to thermo-responsive nanocarriers.
2018
Halloysite nanotubes were functionalized with stimuli-responsive macromolecules to generate smart nanohybrids. Poly(N-isopropylacrylamide)-co-methacrylic acid (PNIPAAM-co-MA) was selectively adsorbed into halloysite lumen by exploiting electrostatic interactions. Amine-terminated PNIPAAM polymer was also investigated that selectively interacts with the outer surface of the nanotubes. The adsorption site has a profound effect on the thermodynamic behavior and therefore temperature responsive features of the hybrid material. The drug release kinetics was investigated by using diclofenac as a non-steroidal anti-inflammatory drug model. The release kinetics depends on the nanoarchitecture of th…