Chitosan-Gold Nanoparticle Composites for Biomedical Application

The aim of this work is to synthesize chitosan-gold nanoparticles films by direct chemical reduction of HAuCl4 in a chitosan solution and to investigate the influence of gold nanoparticles concentration on the structure of films, conductivity and healing effect on mice skin after surgery. Results obtained have shown that new chitosan-gold nanoparticle-collagen bionananocomposites demonstrated better healing effect on the mice skin after surgery than control performed on commercial TheraFormTM material. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3540

Correction: Porous monoliths synthesized via polymerization of styrene and divinyl benzene in nonaqueous deep-eutectic solvent-based HIPEs (RSC Advances (2015) 5 (23255-23260) DOI: 10.1039/C5RA02374B)

© 2018 The Royal Society of Chemistry. The authors regret that there was an error in the results and discussion section of the original article. On page 23257, the text read, The surfactant employed here was sorbitan monooleate . This should have read, The surfactant employed here was sorbitan stearate . The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers

Controlled release of lidocaine hydrochloride from polymerized drug-based deep-eutectic solvents

© The Royal Society of Chemistry 2014. This work takes advantage of the transformation of lidocaine hydrochloride into deep-eutectic solvents (DESs) - ionic liquid analogues - to incorporate polymerizable counterparts into DESs, such that polymer-drug complexes are synthesized by free-radical frontal polymerization without the use of a solvent. DESs are formed through hydrogen bonding of an ammonium salt with a hydrogen-bond donor (HBD). It is demonstrated that lidocaine hydrochloride - as the ammonium salt - is able to form DESs with acrylic acid and methacrylic acid. The properties of DESs allow frontal polymerization in the bulk with full conversion achieved in a one-pot synthesis, yielding monoliths of polymers loaded with a high concentration of drug. In in vitro experiments, the sustained release of the drug takes place in a controlled manner triggered by the pH, ionic strength and solubility of the drug in the medium. Such control is owed to the swelling of polymers as well as to the specific interactions between the drug and the polymers already established in the DES precursor. Finally, it is noteworthy that different monomers (such as HBD) and crosslinkers can be used, thus expanding the possibilities of drug delivery systems for transdermal technologies by exploiting the DES chemistry

Synthesis of biodegradable macroporous poly(l-lactide)/poly(ε-caprolactone) blend using oil-in-eutectic-mixture high-internal-phase emulsions as template

We have demonstrated that l-lactide (LLA) forms a eutectic mixture with ϵ-caprolactone (CL) in a 30:70 mol ratio with a melting point of -19 °C. Taking advantage of the liquid nature and polarity at the LLA-CL eutectic mixture, we have formulated oil-in-eutectic-mixture high-internal-phase emulsions (HIPEs) by stepwise addition of the oil phase (tetradecane) into the continuous phase (mixture of surfactant and LLA-CL eutectic mixture) at room temperature and under stirring. The oil-in-LLA-CL-eutectic-mixture HIPEs were polymerized in the presence of both the organocatalysts 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and methanesulfonic acid (MSA) and the initiator benzyl alcohol (BnOH) at 37 °C and without the addition of any extra reagent or solvent in one single pot. The catalytic selectivities of DBU and MSA for the ring-opening polymerizations of LLA and CL, respectively, allowed the synthesis of macroporous poly(l-lactide)/poly(ϵ-caprolactone) blend materials. The resulting materials exhibited a macroporous morphology that resembled that of the HIPE internal-phase droplets used as templates. These materials proved effective as oil absorbents for oil/water separation with not only a noticeable performance, similar to that of conventional sorbents in terms of both selectivity and recyclability, but also unprecedented safe disposability, certainly of interest for applications in the cleanup of industrial oily wastewaters and oil spills, thanks to the biodegradable features of both poly(ϵ-caprolactone) and poly(l-lactide)

Relationship between polymer chain conformation and phase boundaries in a supercritical fluid

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Porous monoliths synthesized via polymerization of styrene and divinyl benzene in nonaqueous deep-eutectic solvent-based HIPEs

Stable nonaqueous high internal phase emulsions (HIPEs) were prepared and thermally polymerized to yield poly(HIPEs). The internal phase accounting for 80 vol% of the HIPE consisted of a deep-eutectic solvent (DES) while the continuous one comprised styrene and divinyl benzene in a 10:1 molar ratio. DESs with different viscosities were used as an internal phase: choline chloride combined with urea, glycerol or ethylene glycol in a 1:2, salt:hydrogen bond donor molar ratio, respectively. HIPEs were stabilized with different amounts of the surfactant Span 60 (10, 20 and 50 wt% with respect to the total amount of monomers). DESs viscosity and the amount of surfactant employed impact the morphology and mechanical properties of poly(HIPEs). Resulting poly(HIPEs) showed interconnected porosity and high thermal stability above 310 °C. It's worth noting that DES was recovered from 89 to nearly 95 wt% and the monomer conversion was as high as 0.96. In addition, water-in-oil HIPEs were stabilized and then polymerized under the same conditions, but the porous structure of the resulting poly(HIPEs) collapsed. This research demonstrates that DESs are a suitable internal phase for HIPEs thus expanding on the range of monomers forming polymerizable DES-based HIPEs.This paper was written under the auspices of CONACYT through Estancias postdoctorales en el extranjero and Cátedras CONACYT programs, for which MGPG and JDMM are grateful. GLB acknowledges CONACYT project 181678. FDM acknowledges project MAT2012-34811