Design of plant-based bigels by incorporating candelilla wax oleogel and xanthan gum hydrogel for oral curcumin delivery.

This study evaluated the role of plant-based biphasic gel (bigel) formulations prepared using various ratios of xanthan gum (XG) hydrogel and Candelilla wax-based oleogel for the delayed release of curcumin (CUR). Microscopic studies revealed that the bigel exhibited a bicontinuous phase distribution. FTIR analysis suggested increased hydrogen bonding with a higher proportion of hydrogel in the bigel formulations.

Nitrodopamine modified MnO NS-MoSQDs hybrid nanocomposite for the extracellular and intracellular detection of glutathione.

We have developed a highly sensitive and reliable fluorescence resonance energy transfer (FRET) probe using nitro-dopamine (ND) and dopamine (DA) coated MnO nanosheet (ND@MnO NS and DA@MnO NS) as an energy acceptor and MoS quantum dots (QDs) as an energy donor. By employing surface-modified MnO NS, we can effectively reduce the fluorescence intensity of MoS QDs through FRET. It can reduce MnO NS to Mn and facilitate the fluorescence recovery of the MoS QDs.

Preparation and Characterization of Novel Oleogels Using Jasmine Floral Wax and Wheat Germ Oil for Oral Delivery of Curcumin.

Oleogels (OGs) have gained a lot of interest as a delivery system for a variety of pharmaceuticals. The current study explains the development of jasmine floral wax (JFW) and wheat germ oil (WGO)-based OGs for oral drug (curcumin) delivery application. The OGs were made by dissolving JFW in WGO at 70 °C and cooling it to room temperature (25 °C).

Mucus-penetrating nanoparticles based on chitosan grafted with various non-ionic polymers: Synthesis, structural characterisation and diffusion studies.

Transmucosal administration offers numerous advantages for drug delivery as it usually helps to avoid first pass metabolism, provides rapid onset of action, and is a non-invasive route. Mucosal surfaces are covered by a viscoelastic mucus gel layer which acts as a protective barrier preventing the entrance of harmful substances into the human tissues. This function of mucus also inhibits the diffusion of drugs and nano-formulations and can result in a significant reduction of their efficacy.

,-Ru(II)--cymene-poly(-vinylpyrrolidone) surface functionalized gold nanoparticles: from organoruthenium complex to nanomaterial for antiproliferative activity.

Organometallic Ru-arene complexes are promising as anticancer agents, but the lack of tumor uptake and poor solubility in the physiological medium impede their development. In order to deal with these challenges, we developed gold nanoparticles coated with Ru(arene)-functionalized PNVP-Py, where PNVP-Py is pyridine end-functionalized poly(N-vinylpyrrolidone). It is demonstrated that these particles exhibit higher anti-proliferative activity than the individual organometallic ruthenium(ii) complex of the type [Ru(η6-p-cymene)(NN)Cl]PF6, where NN is bis(4-methoxyphenylimino)acenaphthene, against colorectal adenocarcinoma cell lines.

Graphene Oxide Increases Corneal Permeation of Ciprofloxacin Hydrochloride from Oleogels: A Study with Cocoa Butter-Based Oleogels.

In this work, oleogels of cocoa butter (CB), rice bran oil (RBO), and graphene oxide (GO) were prepared. The prepared oleogels were subjected to various characterization techniques such as bright-field microscopy, X-ray diffraction (XRD), crystallization kinetics, differential scanning calorimetry (DSC), and mechanical studies. The influence of increasing GO content on the in vitro drug release and ex vivo corneal permeation of the model drug (ciprofloxacin HCl-CPH) from the oleogels was also investigated.

Carrageenan: A Wonder Polymer from Marine Algae for Potential Drug Delivery Applications.

Background: With the advancement in the field of medical science, the idea of sustained release of the therapeutic agents in the patient's body has remained a major thrust for developing advanced drug delivery systems (DDSs). The critical requirement for fabricating these DDSs is to facilitate the delivery of their cargos in a spatio-temporal and pharmacokinetically-controlled manner. Albeit the synthetic polymer-based DDSs normally address the above-mentioned conditions, their potential cytotoxicity and high cost have ultimately constrained their success.

Selective Detection of Trinitrophenol by Amphiphilic Dimethylaminopyridine-Appended Zn(II)phthalocyanines at the Near-Infrared Region.

Novel amphiphilic Zn(II)phthalocyanines (ZnPcs) peripherally substituted with four and eight dimethylaminopyridinium units (ZnPc and ZnPc) were synthesized by cyclotetramerization of the corresponding phthalonitriles. The effect of aggregation and photophysical (fluorescence quantum yields and lifetimes) and photochemical (singlet oxygen generation and photodegradation under light irradiation) properties was investigated. The chemosensing ability of ZnPcs toward explosive nitroaromatic compounds was explored in aqueous medium.

Waterborne Electrospinning of Poly(N-isopropylacrylamide) by Control of Environmental Parameters.

With increasing toxicity and environmental concerns, electrospinning from water, i.e., waterborne electrospinning, is crucial to further exploit the resulting nanofiber potential.

Enhanced Bioactivity of α-Tocopheryl Succinate Based Block Copolymer Nanoparticles by Reduced Hydrophobicity.

Well-structured amphiphilic copolymers are necessary to obtain self-assembled nanoparticles (NPs) based on synthetic polymers. Highly homogeneous and monodispersed macromolecules obtained by controlled polymerization have successfully been used for this purpose. However, disaggregation of the organized macromolecules is desired when a bioactive element, such as α-tocopheryl succinate, is introduced in self-assembled NPs and this element must be exposed or released to exert its action.

Salt-Driven Deposition of Thermoresponsive Polymer-Coated Metal Nanoparticles on Solid Substrates.

Here we report on a simple, generally applicable method for depositing metal nanoparticles on a wide variety of solid surfaces under all aqueous conditions. Noble-metal nanoparticles obtained by citrate reduction followed by coating with thermoresponsive polymers spontaneously form a monolayer-like structure on a wide variety of substrates in presence of sodium chloride whereas this phenomenon does not occur in salt-free medium. Interestingly, this phenomenon occurs below the cloud point temperature of the polymers and we hypothesize that salt ion-induced screening of electrostatic charges on the nanoparticle surface entropically favors hydrophobic association between the polymer-coated nanoparticles and a hydrophobic substrate.

α-Tocopheryl succinate-based amphiphilic block copolymers obtained by RAFT and their nanoparticles for the treatment of cancer.

α-Tocopheryl succinate (α-TOS) is a well-known mitochondrially targeted anticancer compound. However, the major factor limiting the use of α-TOS is its low solubility in physiological media. To overcome this problem, the aim of this work is the preparation of new polymeric and active α-TOS-based nanovehicle with a precise control over its macromolecular architecture.

Reversible Calcium(II)-Ion Binding through an Apparent pKa Shift of Thermosensitive Block-Copolymer Micelles.

There is an increasing need for smart materials capable of removing multivalent ions from aqueous streams without the inconvenience of brine regeneration as in ion-exchange processes. Herein, we present a thermoresponsive micellar system consisting of polystyrene-poly(methoxy diethyleneglycol acrylate) block copolymer surfactants modified with carboxylic acid end groups (PS-PMDEGA-COOH) that can be used to switch between the adsorption and desorption of divalent calcium(II) cations by a mild temperature trigger, thus providing a new type of thermoregenerable ion-adsorbing materials. The switch of calcium(II)-binding capacity is demonstrated to result from a shift in the pKa value of the carboxylic acid groups by the collapse and redissolution of the PMDEGA block and the associated change in local polarity.

Linear polyethylenimine as (multi) functional initiator for organocatalytic l-lactide polymerization.

The preparation of polyethylenimine (PEI)-polylactide (PLA) copolymer structures is promising as these materials may find use in gene and/or drug delivery applications. In the current work we have explored the utilization of linear polyethylenimine (L-PEI) as multifunctional initiator for the organocatalytic ring-opening polymerization of lactide. Evaluation of the effect of the amount of catalyst revealed that with high catalyst loadings mixtures of unmodified L-PEI and PEI-PLA were obtained while low catalyst loadings leads to efficient preparation of PEI-PLA graft copolymers.

Tuning the LCST and UCST thermoresponsive behavior of poly(N,N-dimethylaminoethyl methacrylate) by electrostatic interactions with trivalent metal hexacyano anions and copolymerization.

Poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) has been reported to show both upper critical solution temperature (UCST) and lower critical solution temperature (LCST) behavior in presence of trivalent metal hexacyano anions, which is attractive for the development of smart materials. In this communication, the influence of the double thermoresponsive behavior of PDMAEMA driven by electrostatic interactions is investigated by comparing systems with [Co(CN)6 ](3-) , [Fe(CN)6 ](3-) , and [Cr(CN)6 ](3-) as trivalent anions. Furthermore, tuning of double thermoresponsive behavior of PDMAEMA by incorporating hydrophilic or hydrophobic comonomers is also discussed in the presence of [Fe(CN)6 ](3-) as trivalent ion.

Hydrogen bonded multilayer films based on poly(2-oxazoline)s and tannic acid.

In recent years, the layer-by-layer (LbL) assembly based on hydrogen bonding interactions is gaining popularity for the preparation of thin film coatings, especially for biomedical purposes, based on the use of neutral, non-toxic building blocks. The use of tannic acid (TA) as hydrogen bonding donor is especially interesting as it results in LbL films that are stable under physiological conditions. In this work, investigations on the LbL thin film preparation of TA with poly(2-oxazoline)s with varying hydrophilicity, namely poly(2-methyl-2-oxazoline) (PMeOx), poly(2-ethyl-2-oxazoline) (PEtOx) and poly(2-n-propyl-2-oxazoline) (PnPropOx), are reported.

RAFT polymerization of 4-vinylphenylboronic acid as the basis for micellar sugar sensors.

Well-defined homo and mPEGylated block (co)polymers of the commercially available unprotected 4-vinylphenylboronic acid (4-VBA) monomer are reported based on reversible addition-fragmentation chain transfer (RAFT) polymerization. The polymerization kinetics are studied in detail for homo and block (co)polymerizations with different chain transfer agents (CTAs) to optimize the preparation of well-defined polymer structures, eventually leading to comparatively low dispersities (Đ ≤ 1.25).

Antimicrobial hydantoin-grafted poly(ε-caprolactone) by ring-opening polymerization and click chemistry.

Novel degradable and antibacterial polycaprolactone-based polymers are reported in this work. The polyesters with pendent propargyl groups are successfully prepared by ring-opening polymerization and subsequently used to graft antibacterial hydantoin moieties via click chemistry by a copper(I)-catalyzed azide-alkyne cycloaddition reaction. The well-controlled chemical structures of the grafted copolymers and its precursors are verified by FT-IR spectroscopy, NMR spectroscopy, and GPC characterizations.

Antimicrobial hydantoin-containing polyesters.

A new N-hydantoin-containing biocompatible and enzymatically degradable polyester with antibacterial properties is presented. Different polyesters of dimethyl succinate, 1,4-butanediol, and 3-[N,N-di(β-hydroxyethyl)aminoethyl]-5,5-dimethylhydantoin in varying molar ratios are prepared via two-step melt polycondensation. The antibacterially active N-halamine form is obtained by subsequent chlorination of the polyesters with sodium hypochlorite.