Organogels, hydrogels and bigels as transdermal delivery systems for diltiazem hydrochloride

In the present study,gel formulations of organogels,hydrogels,and oleo-hydrogel(bigels)were evaluated as transdermal drug delivery systems for diltiazem HCL(DH).Organogels were prepared using soya-bean oil(SO)as a solvent and span 60(Sp 60),cetyl alcohol(CA)or lecithinpluronic(PLO)as organogelators without and with different surfactants(2%w/w)namely span 80(Sp80),tween 20(T20)and tween 80(T80).On the other hand,hydrogels were formulated using Hydroxypropyl-methylcellulose(HPMC)polymer and bigels were prepared by mixing organogels with HPMC hydrogels.The prepared gels were analyzed microscopically,thermally by DTA and for pH,and viscosity.The effect of gelator used,surfactant types and pH of the sink on DH release from cellophane membrane was investigated.In addition,the DH permeability across the rabbit skin was evaluated.Finally,the in vivo performance of various gel formulationswas assessed based on the hypotensive effects of the drug using hypertensive albino male rat models.The microscopical analysis indicated that the solid fibers formed by gelator particles form the backbone of the organogels while bigels appeared as emulsion like.The addition of surfactants showed an increase in organogel viscosity.The thermal analysis of organogels indicated that the drug present in amorphous not in crystalline form.The release studies indicated that DH release from organogels,hydrogels and bigels could be controlled.The included surfactants decreased the DH release and permeation from organogels compared to those without surfactants using either Sp60 or CA.HPMC hydrogel and Bigels showed higher DH release and permeation rates when compared to organogels.The percent DH released in different pH values was in the following descending order:pH5.5>pH1.2>pH6.8>pH7.4.The in vivo antihypertensive activity of DH using different transdermal gels is arranged as following:hydrogels>PLO organogel>bigel>Sp 60 organogel.

Fluoride-Responsive Organogel Based on Hydrazide Derivatives

An organogelator named N-[3-(hydroxy)-4-(dodecyloxy)-benzoyl]-N’ (4’-nitro-benzoyl) hydrazide (D12) was synthesized. It could form stable gels in some of the tested organic solvent. SEM images revealed that the molecules self- assembled into fibrous aggregates in the xerogels. The X-ray diffraction analysis showed that the xerogel exhibited a layered structure. FT-IR studies confirmed that intermolecular hydrogen bonding between C=O and N-H groups was the major driving force for gelation of organic solvents. The gel exhibited gel-sol transition and color change upon addition of F- . An extended conjugated system formed through the phenyl group and a five-membered ring based on intramolecular hydro-gen bonding between the oxygen atom near the deprotonation nitrogen atom and the other NH, which is responsible for the dramatic color change upon addition of F- .

Synthesis and Self-assembling of Coumarin-based Low-molecular Weight Organogelators

Four coumarin derivatives(4a―4d) with different alkoxy chains were synthesized. It was found that compound 4d showed a better gelation ability than the other compounds, for example, it could self-assemble into organogels in various organic fluids via ultrasound treatment or heating-cooling process, whereas compound 4c could only gel in a few mixed solvents and compounds 4a, 4b could not form organogel. The results from fluorescent and FT-IR spectra indicate that π-π interaction had an effect on the formation of the organogels of compound 4d besides H-bonding and van der Waals interaction, which were the driving forces for the self-assembling of compound 4c in gel state. The gel of compound 4d in toluene could emit strong fluorescence under UV irradiation and the [2+2] cyc-lo-addition was suggested by 1H NMR and fluorescence spectroscopy. This light-sensitive organogel might find application in optical materials.

Scalable and Robust Bio-inspired Organogel Coating by Spraying Method Towards Dynamic Anti-scaling

Scaling usually causes serious problems in daily life and industrial production.Currently,developing passive anti-scaling coatings has shown promises to overcome this problem.In this work,we fabricated a scalable and robust bio-inspired organogel(BIO)coating,showing dynamic scale resistance in the oil/brine mixture.The oil layer of the BIO coating was utilized as a barrier to inhibit scale nucleation and reduce scale adhesion.The mechanical strength of the coating was optimized by regulating nanoparticle contents.Moreover,the universality of scale resistance was demonstrated by varying the types of nanoparticles,oils and scales.Compared with commercial pipeline materials,such as copper,this BIO coating significantly reduces scale deposition after 240-h scaling test(ca.93%reduction).Therefore,this study designs scalable and robust organogel coatings for sustainable scale resistance,which may be used for practical application in oil production.

Wet‑Spinning Knittable Hygroscopic Organogel Fibers Toward Moisture‑Capture‑Enabled Multifunctional Devices

Atmospheric moisture exploitation is emerging as a promising alternative to relieve the shortage of freshwater and energy.Efforts to exploit hygroscopic materials featuring flexibility,programmability,and accessibility are crucial to portable and adaptable devices.However,current two-dimensional(2D)or three-dimensional(3D)-based hygroscopic materials are dif-ficult to adapt to diverse irregular surfaces and meet breathability,which severely hinders their wide applications in wearable and programmable devices.Herein,hygroscopic organogel fibers(HOGFs)were designed via a wet-spinning strategy.The achieved fibers were composed of the hydrophilic polymeric network,hygroscopic solvent,and photothermal/antibacterial Ag nanoparticles(AgNPs),enabling hygroscopic capacity,photothermal conversion,and antibacterial.Owing to the good knittable feature,the HOGFs can be readily woven to adjusted 2D textiles to function as an efficient self-sustained solar evaporator of 4-layer woven HOGF device with a saturated moisture capacity of 1.63 kg m^(-2) and water-releasing rate of 1.46 kg m^(-2) h^(-1).Furthermore,the 2D textile can be applied as a wearable dehumidification device to efficiently remove the evaporative moisture from human skin to maintain a comfortable environment.It can reduce the humidity from 90 to 33.4%within 12.5 min.In addition,the introduction of AgNPs can also endow the HOGFs with antibacterial features,demonstrat-ing significant potential in personal healthcare.

双凝胶在食品领域:从组成到应用

双凝胶是油凝胶和水凝胶在一定温度下剪切混合制成的双相体系。作为一种两亲性半固体制剂,双凝胶具有良好的稳定性、包埋特性、加工特性等,引起了人们的广泛关注。双凝胶在替代传统固体脂肪,提高复合食品的营养价值以及递送生物活性物质方面有巨大的潜力。本文综述了双凝胶的组成及合成方法,并梳理了双凝胶的种类,总结了双凝胶在食品领域的主要应用进展,并展望其发展前景,以期为双凝胶在食品领域的进一步研究和应用提供一定的指导。

一种有机凝胶因子对二氧化碳可视化传感的综合实验设计

合成了一种萘酰亚胺衍生的有机凝胶因子,测试了其二甲基亚砜(DMSO)凝胶在氟离子诱导下形成的溶液对气流和空气中二氧化碳可视化传感的能力。实验涉及有机合成、性能测试和仪器分析等基本操作,并利用理论知识对分子传感机理进行分析,可以培养学生多种实验技能的综合运用能力和独立分析能力。

Nanomagnetic Organogel Based on Dodecyl Methacrylate for Absorption and Removal of Organic Solvents

A novel nanomagnetic organogel was synthesized by in situ emulsion polymerization-crosslinking method using dodecyl methacrylate(DDMA) and styrene(St) as monomers, divinylbenzene(DVB) as a crosslinking agent, azobisisobutyronitrile(AIBN) as an initiator, and Fe_3O_4 as a nanomagnetic particle. Modification of the network was carried out by inclusion of the multi-walled carbon nanotubes(MWCNT) into the organogel matrix. The structure of the nanocomposite was characterized using FTIR spectroscopy, SEM,TEM, TGA/DTG, VSM, and BET analysis. The effects of various parameters such as the amount of crosslinker, initiator, Fe_3O_4, and reaction time as well as monomer ratio on the oil absorption of the organogel were studied. The synthesized organogel can absorb about35.5, 22.1, 29.86, 14.58, 17.6, 15.3, and 13.7 g·g^(-1) of CHCl_3, toluene, CH_2Cl_2, hexane, crude oil, gasoline, and diesel oil, under the optimized polymerization conditions, respectively. The nanocomposite organogels can be easily separated by a magnetic field after absorption of organic solvents.

Effects of Main-chain and Chain-ends on the Organogelation of Stearoyl Appended Pendant Valine Based Polymers

In this work, we investigated the effect of hydrophobic interactions between the polymeric backbone and chain-end groups on the self-assembly pathway of stearoyl appended side-chain valine (Val)-based poly(methacrylate/acrylate) homopolymers in different organic hydrocarbons. Gelation studies conducted revealed that while polymers with polyacrylate as backbone induces gelation in several organic hydrocarbons, polymers with polymethacrylate in the main-chain significantly hinders macroscopic gelation. Morphology of the organogels was analysed by field emission scanning electron microscopy (FESEM), and mechanical strengths of the organogels were determined by rheological measurements. Reversible addition-fragmentation chain transfer (RAFT) polymerization chain transfer agents (CTA)s,[R1 —S—C=(S)—S—R2] with different —Ri and — R2 groups, have been employed to study the effect of structural variation at the chain-end on macroscopic assembly mechanism. We found that the additional interactions between terminal groups via hydrogenbonding or n-n stacking interactions or both help to build up the self-assembly pathway and thereby produces mechanically stable organogels.

A phase-selective,bis-urea organogelator with a curved bis-naphthalene core

A phase-selective,bis-urea organogelator with a curved bis-naphthalene core was synthesized and characterized.This gelator is capable of gelating a variety of hydrocarbons and oils.The resulting gels have been characterized by rheology,SEM,and molecular modelling.The gelator can be applied in the powder form for the recovery of a thin layer of petrol oil spill in water.

Lecithin organogel: A unique micellar system for the delivery of bioactive agents in the treatment of skin aging

Skin aging is an unavoidable aspect of human life.Premature skin aging can result from poor care,environmental pollutants,and ultraviolet radiation exposure.Wrinkles,lines,spots,uneven skin tone,and pigmentation are often indicators of skin aging.One cannot avoid aging but cosmetics and pharmaceutical approaches can minimize and delay the damage.Topical applications of biocompatible and biodegradable vehicles have been explored for delivering anti-aging compounds.Lecithin organogel(LO)is an effective vehicle for topical delivery of many bioactive agents used in aging treatment.Lecithin is cell component isolated from soya beans or eggs and purified to show excellent gelation in non-polar solvents when combined with water.LO can form a heat-stable,resistant to microbial growth,visco-elastic,optically transparent,and non-birefringent micellar system.It serves as an organic medium to enhance dermal permeation of poorly permeable drugs by effectively partitioning into the skin.Its ability to dissolve in hydrophilic as well as in lipophilic drugs makes it a dynamic vehicle,which can be explored as a carrier for anti-aging agents.

Intermolecular hydrogen-bond interaction to promote thermoreversible 2'-deoxyuridine-based AIE-organogels

Fluorescent supramolecular nucleoside-based organogels or hydrogels have attracted increasing attention owing to their tunable stability,drug delivery,tissue engineering,and inherent biocompatibility for applications in designing sensors.As the temperature of a constant TPE-Octa-dU gelato r at MGC as low as 0.2 wt%was increased with gel to sol transition,a progressive decrease in the fluorescence intensity was observed.~1 H NMR study in ethanol-d_(6)/H_(2)O revealed the existence of intermolecular hydrogen-bond interaction between uridine nucleobase and triazole moieties.Based on these experiments,thus organogels induced by hydrogen bonding can promote an aggregation-induced emission(AIE)of TPE moiety.Thermoreversible gelation properties have been investigated systematically,including AIE-shapemorphing architecture owing to their unique solid-liquid interface and easy processability.At the same line,the related TPE-EdU derivative which was synthesized from 5-ethynyl-2'-deoxyuridine does not delive r organogels or hydrogels,a nd under similar circumstances TPE moiety of TPE-EdU does not efficiently exhibit AIE phenomenon either.

Oleophobic interaction mediated slippery organogels with ameliorated mechanical performance and satisfactory fouling-resistance

Owing to their inherent semi-solid property and lubricant ability,organogels manifest various unique characteristics and serve as promising candidates for antifouling.However,the poor mechanical properties of organogels often limit their practical applications.Herein,we report a simple and effective method to prepare organogels with reinforced mechanical performance and surface lubricant ability with the synergistic roles played by oleophobic and oleophilic chains.The rigid oleophobic chains have a poor affinity to lubricating solvent,which gives rise to high oleophobic interactions between polymer networks;the soft oleophilic chains possess a high affinity to the low surface energy solvent,which lead to high solvent content to maintain the satisfactory lubricant capacity.The organogel of oleophobic methyl methacrylate(MMA)and oleophilic lauryl methacrylate(LMA)is chosen as a representative example to illustrate this concept.With the optimal composition,the as-prepared organogels offer satisfactory tensile fracture stress,fracture strain,Young’s modulus,toughness,and tearing fracture energy of 480 k Pa,550%,202 k Pa,1.14 MJ m,and 5.14 k J m,respectively,which are far beyond the classical PLMA organogels.Furthermore,the biofouling resistance tests demonstrate 4 to 9-fold reduction of protein and bacteria adhesion on the reinforced organogels surface in comparison to the glass substrate and solvent-free dry organogels.This simple and effective approach to toughen organogels,we hope,can be applied in various fields with different practical functional requirements in the future.

Self-Assembly of Schiff Base Organogelator with Enhanced Fluorescence Emission

A new organogelator based on Schiff base derivative has been designed and synthesized.It can be employed as building blocks to fabricate organic nano-or micro-structures.It shows excellent self-assembling properties.It could form stable gels with nanofiber structures in various organic solvents,such as n-butanol,benzyl alcohol,ethyl acetate,acetone,aniline.The gelation properties,structural characteristics and fluorescence of the gels were studied.Compared with the solution,the gel showed significantly enhanced emission.This organogel system can be used as a thermally driven fluorescence molecular switch.

Water-resistant conductive organogels with sensation and actuation functions for artificial neuro-sensory muscular systems

The development of functional flexible conductive materials can significantly contribute to the improvement of intelligent human–computer integration.However,it is a challenge to endow human–machine interface with perception and response actuation simultaneously.Herein,a customizable and multifunctional electronic conductive organogel is proposed by combining conductive carbon nanotube(CNT)clusters and flexible adhesive organogels.The conductive CNT cluster layers generated on the surface of organogels equip the resulting organogel-based conductors with considerable quasi-superhydrophobicity and increase their potential applicability as highly sensitive stress and strain sensors.In particular,this quasi-superhydrophobicity is insensitive to tensile strain.Based on customizable conductive networks and entropy-driven organogel actuation,the conductive organogels can sense various strain and stress signals and imitate natural organisms with muscle actuation and neurofeedback.This strategy for preparing electronic conductors can enhance the rational design of soft robotics and artificial intelligence devices,facilitating further progress of human-like intelligent systems.

Towards a universal organogelator:A general mixing approach to fabricate various organic compounds into organogels

Low-molecular-weight organogels(LMOG) have been attracting a surge interest in fabricating soft materials.Although the finding of the gelator molecules has been developed from serendipity to objective design,the achievement of the gelator molecules still needs good design and tedious organic synthesis.In this paper,we proposed a simple and general mixing approach to get the organogel for nearly all the organic compounds and even soluble nanoparticles without any modification.We have designed a universal gelator molecule,which forms organogels with more than 40 kinds of organic solvents from aploar to polar solvents.More interestingly,when other organic compounds or even nanomaterials,which are soluble in certain organic solvents,are mixed with this gelator molecule,they can form organogels no matter whether the individual compounds could form organogel or not.This method is applicable to nearly all kinds of soluble organic compounds and opens an efficient and universal way to fabricate gel materials.

Organogelators based on p-alkoxylbenzamide and their self-assembling properties

展示长烷基链的一系列 p-alkoxylbenzamides 被综合了并且是乐意地在许多器官的溶剂形成稳定的胶化。他们的自己组装性质和结构性质关系被扫描电子显微镜学调查， X 光检查衍射， 1 H 原子磁性的回声，和 Fourier 变换红外线的光谱学。形成的胶化对象温度和氟化物阴离子那样的环境刺激多应答。结果显示出那结合的氢的联合， - 叠并且在 p-alkoxylbenzamides 到的聚集的货车 der Waals 相互作用结果形成三尺寸的网络，取决于长烷基链的长度。

Ultrasound responsive organogels based on cholesterol-appended quinacridone derivatives with mechanochromic behaviors

A series of cholesterol-appended quinacridone (QA) derivatives 1a-1d have been synthesized,in which 1b and 1c could form stable organogels in a wide range of organic solvents upon ultrasound irradiation.Field emission scanning electronic microscope (FESEM) and transmission electron microscopy (TEM) of xerogels or precipitates indicated that 1b and 1c formed 1D fibrous nanostructure,while 1a assembled into 3D flower-like microstructures.The ultrasound-induced organogel process was characterized by kinetic UV-vis and photoluminescence spectroscopic methods suggesting the formation of ?-? aggregates in the gel state.Experimental results demonstrated that the ultrasound could promote molecules to contact frequently in the solution and induce semistable initial aggregates,which propagate to form nano/micro superstructures.The aggregation model was optimized by semiempirical AM1 calculation suggesting the hierarchical self-assembly process.In addition,the formed xerogel film exhibited mechanochromic property,and the phase transition process was accompanied by the fluorescence changes between yellowish green and orange.

Coordinated organogel templated fabrication of silver/polypyrrole composite nanowires

制作金属 / 行为聚合物的一个新方法合成 nanowires 被拿 silver/polypyrrole 介绍合成 nanowires 作为一个例子。当模板第一被准备，银(I) 协调了 organogel，并且吡咯的氧化还原作用聚合发生在胶化纤维上，给 silver/polypyrrole nanowires 的产品。silver/polypyrrole nanowires 被多重技术描绘。这策略能在房间温度在一步舞过程被执行，并且它在聚合物 nanostructures 的模板合成证明协调 organogels 的实用程序。