N-isopropylacrylamide Monomer Research Articles

Cartilage-Inspired, High-Strength, and Heat-Tolerant Lubricating Hydrogels by Macrophase Separation.

Hydrogels are considered as a potential cartilage replacement material based on their structure being similar to natural cartilage, which are of great significance in repairing cartilage defects. However, it is difficult for the existing hydrogels to combine the high load bearing and low friction properties (37 °C) of cartilage through sample methods. Herein, we report a facile and new fabrication strategy to construct the PNIPAm/EYL hydrogel by using the macrophase separation of supersaturated N-isopropylacrylamide (NIPAm) monomer solution to promote the formation of liposomes from egg yolk lecithin (EYL) and asymmetric template method. The PNIPAm/EYL hydrogels possess a relatively high compressive strength (more than 12 MPa), fracture energy (9820 J/m2), good fatigue resistance, lubricating properties, and excellent biocompatibility. Compared with the PNIPAm hydrogel, the friction coefficient (COF 0.046) of PNIPAm/EYL hydrogel is reduced by 50%. More importantly, the COF (0.056) of PNIPAm/EYL hydrogel above lower critical solution temperature (LCST) does not increase significantly, exhibiting heat-tolerant lubricity. The finite element analysis further proves that PNIPAm/EYL hydrogel can effectively disperse the applied stress and dissipate energy under load conditions. This work not only provides new insights for the design of high-strength lubricating hydrogels but also lays a foundation for the treatment of cartilage injury as a substitute material.

Preparation of Crust Type Dust Suppression Gel Based on Plant Extraction Technology for Ginkgo biloba Leaves: Characterization, Properties, and Function Mechanism

The coal industry plays an essential role in China’s economic development, and issues such as occupational health and environmental pollution caused by coal dust have attracted a great deal of attention. In accordance with the principles of environmental protection and waste management, this study used carboxymethyl ginkgo cellulose (CL) extracted and modified from Ginkgo biloba leaves as a matrix, and a graft copolymerized with sodium 3-allyloxy-1-hydroxy-1-propanesulfonate (AHPS) and N-isopropylacrylamide (NIPAM) monomers to prepare low-cost, environmentally friendly, and high-performance coal dust suppression (C-A-N). By optimizing fitting experimental data through three factors and two response surface analyses, the optimal dust suppression efficiency ratio was determined to be 4:8:5, and its swelling and water retention properties were analyzed. The microstructure, chemical reaction process, combustion performance and crusting property of the dust suppression gel were analyzed using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetry (TG), scanning electron microscopy (SEM), cone calorimetry, and consolidation layer strength tests. Relevant experiments show that the dust suppression gel prepared in this study has the characteristics of a strong wettability and minor impacts on the calorific value of coal, as well as green and environmental protection. When the wind speed is 10 m/s, the dust suppression effect reaches 93%, and the hardness of the solidified layer reaches 39.6 KPa. This study analyzed the migration and combination of functional groups in the interaction system using molecular dynamics simulation software. The microscopic effect and mechanism between dust suppression gel and coal are revealed from a molecular point of view. The feasibility and accuracy of the molecular dynamics simulation were verified by the consistency between simulation results and experimental data. Therefore, combining the utilization of waste resources with dust suppression can have important economic and social benefits.

Revisiting Protein-Copolymer Binding Mechanisms: Insights beyond the "Lock-and-Key" Model.

The "lock-and-key" model that emphasizes the concept of chemical-structural complementary is the key mechanism for explaining the selectivity between small ligands and a larger adsorbent molecule. In this work, concerning the copolymer chain using only the combination of N-isopropylacrylamide (NIPAm) and hydrophobic N-tert-butylacrylamide (TBAm) monomers and by large-scale atomistic molecular dynamics simulations, our results show that the flexible copolymer chain may exhibit strong binding affinity for the biomarker protein epithelial cell adhesion molecule, in the absence of hydrophobic matching and strong structural complementarity. This surprising binding behavior, which cannot be anticipated by the "lock-and-key" model, can be attributed to the preferential interactions established by the copolymer with the protein's hydrophilic exterior. We observe that increasing the fraction of incorporated TBAm monomers leads to a prevalence of interactions with asparagine and glutamine amino acids due to the emerging hydrogen bonding with both NIPAm and TBAm monomers. Our findings suggest the appearance of highly specific and high-affinity binding sites on the protein created by engineering the copolymer composition, which motivates the applications of copolymers as protein affinity reagents.

Optimization of swelling and mechanical behavior of Acer platanoides cellulose combo hydrogel

To reduce resource scarcity and environmental concerns, it is better to choose both sustainable and biodegradable materials for the synthesis of value-added products. In this study, a biodegradable combo hydrogel was developed that is prone to decompose and possesses high swello-mechanical properties. The combo hydrogel is fabricated through crosslinking of Acrylic acid (AA) and n-isopropyl acrylamide monomers on Acer platanoides cellulose (APC) in the presence of MBA (N, N-methylene bisacrylamide). The APC-combo hydrogel was characterized through SEM, FTIR, swelling, mechanical, and biodegradability tests and got results in favor. SEM images show high crosslinking density and porous surface that facilitates water penetration for swelling behavior. The potential use of cellulose in combo hydrogel helped in intensifying its mechanical and biodegradable properties. APC-combo hydrogel (APC-CH9) has a higher swelling ratio at 2:1 monomer to APC ratio, 0.5 percent MBA concentration, 70% neutralization degree, 40 °C temperature, and pH 6. Similarly, the hydrogel possesses higher values for tensile strength and Young's modulus at 0.6 percent MBA concentration but shows higher compression strength and elongation at break at 0.2% MBA. The high swello-mechanical and moderate biodegradability properties of combo hydrogel make it a promising material for minimizing the agricultural water and nutrient leaching issues and results in reducing plant wither rate.

Multistage safety code based on responsive CdS photonic crystal organohydrogel

In the realms of information storage and display, achieving heightened levels of complexity and security has always been paramount. This study presents a multi-responsive material based on CdS photonic crystals, harnessing the properties of CdS photonic crystals and responsive organohydrogels. We incorporated temperature-responsive monomer N-isopropyl acrylamide (NIPAM), AIE monomer (2-(4-vinylphenyl)ethene-1,1,2-triyl)tribenzene (TPEE), and photochromic unit 2,2-diphenyl-2H-naphtho [1,2-b] pyran-6-carbaldehyde (naphthopyran, Np) into the organohydrogel to prepare the responsive gel material. It was then combined with CdS photonic crystals to fabricate the multistage responsive CdS photonic crystal organohydrogel. This material is not only capable of tuning the structure color of the photonic crystals through temperature but also triggers the AIE effect of the gel upon reaching the phase transition temperature. Additionally, it can initiate the photochromic effect of the material upon exposure to ultraviolet (UV) light. These responsive behaviors underpin the multistage response nature of the material. Capitalizing on these multi-responsive traits, we designed an array of multistage responsive anti-counterfeiting patterns and multistage security codes. This approach not only elevates the density of multi-layered information storage but also fortifies the tamper-resistance of traditional coding systems. The multistage responsive material has a wide spectrum of potential applications, particularly in anti-counterfeiting, information display, and encrypted data transmission, offering fresh perspectives in the domain of information security.

Water contaminant: Use it but do not shield it to synthesize co-polymers with multiple emission colours.

Due to the high affinity with water molecules, amide compounds are easily contaminated by moisture; therefore, the water interference effect cannot be totally excluded from the amide-involved reactions. Thus, the perfect solution is to use the interference effect but not shield it in a real application. In this work, we introduced different contents of sodium acrylate (AAS) to scavenge water from the monomers of N-isopropylacrylamide (NIPAm) when copolymerized with TPA-Vinyl-4CN. Herein, water molecules play a role as nucleophilic reagents to attack highly active functional groups as -C=C-CN from TPA-Vinyl-4CN, leading to a blue emissive TPA-Vinyl-2CHO. From this study, we made a deep awareness of the interactions between three reaction partners of AAS and NIPAm as well as TPA-Vinyl-4CN. Our results clearly demonstrated the fact that water can be perfectly used and controlled by the water absorbent of AAS, developing a new approach to synthesizing multiple emission-coloured polymers by using only one luminogen of TPA-Vinyl-4CN.

Temperature-Sensitive Aerogel Using Bagasse Carboxylated Cellulose Nanocrystals/N-Isopropyl Acrylamide for Controlled Release of Pesticides.

Temperature-sensitive carboxylated cellulose nanocrystals/N-isopropyl acrylamide aerogels (CCNC-NIPAMs) were developed as novel pesticide-controlled release formulas. Ammonium persulfate (APS) one-step oxidation was used to prepare bagasse-based CCNCs, and then the monomer N-isopropyl acrylamide (NIPAM) was successfully introduced and constructed into the temperature-sensitive CCNC-NIPAMs through polymerization. The results of the zeta potential measurement and Fourier infrared transform spectrum (FTIR) show that the average particle size of the CCNCs was 120.9 nm, the average surface potential of the CCNCs was -34.8 mV, and the crystallinity was 62.8%. The primary hydroxyl group on the surface of the CCNCs was replaced by the carboxyl group during oxidation. The morphology and structure of CCNC-NIPAMs were characterized via electron microscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), compression performance, porosity analysis, and thermogravimetric (TG) analysis. The results demonstrate that CCNC-NIPAM has a high porosity and low density, as well as good thermal stability, which is conducive to loading and releasing pesticides. In the swelling, drug loading, and controlled release process, the CCNC-NIPAM exhibited significant temperature sensitivity. Under the same NIPAM reaction amount, the equilibrium swelling rate of the CCNC-NIPAM first increased and then decreased with increasing temperature, and the cumulative drug release ratio of the CCNC-NIPAM at 39 °C was significantly higher than that at 25 °C. The loading efficiency of the CCNC-NIPAM on the model drug thiamethoxam (TXM) was up to 23 wt%, and the first-order model and Korsmyer-Peppas model could be well-fitted in the drug release curves. The study provides a new method for the effective utilization of biomass and pesticides.

Enhancing the mechanical properties of hydrogels with vinyl-functionalized nanocrystalline cellulose as a green crosslinker

Hydrogels have gained significant attention in scientific communities for their versatile applications, but several challenges need to be addressed to exploit their potential fully. Conventional hydrogels suffer from poor mechanical strength, limiting their use in many applications. Moreover, the crosslinking agents used to produce them are often toxic, carcinogenic, and not bio-friendly. This study presents a novel approach to overcome these limitations by using bio-friendly modified nanocrystalline cellulose as a crosslinker to prepare highly stretchable and tough thermosensitive hydrogels. The surface of nanocrystalline cellulose was modified with 3-methacryloxypropyltrimethoxysilane (MPTS) to obtain modified nanocrystalline cellulose (M-NCC) crosslinker and used during free radical polymerization of thermosensitive N-isopropyl acrylamide (NIPA) monomer to synthesize NIPA/M-NCC hydrogel. The resulting nanocomposite hydrogels exhibit superior mechanical, thermal, and temperature-responsive swelling properties compared to conventional hydrogels prepared with traditional bi-functional N, N′-methylene bis (acrylamide) (MBA) as a crosslinker. The elongation at break, tensile strength, and toughness of the NIPA/M-NCC hydrogels significantly increase and Young’s modulus decrease than conventional hydrogel. The designed M-NCC crosslinker could be utilized to improve the mechanical strength of any polymeric elastomer or hydrogel systems produced through chain polymerization.

Synthesis of a porous hollow magnetic molecularly imprinted microsphere by O/W/O composite emulsion polymerization for specifically recognizing bovine serum albumin

Molecular imprinting technology is highly successful for low-molecular-weight molecules, but is still confronted with many challenges for proteins. This study introduces a strategy to synthesize hollow magnetic molecularly imprinted microspheres (HMMIMs) under Fe3O4 magnetic nanoparticles matrix, by oil-in-water-in-oil composite emulsion polymerization with alkylphenol ethoxylates and Span-80 as emulsifiers. The synthesis conditions after optimization were 1.0 mmol thermo-sensitive functional monomer N-isopropylacrylamide, 1.0 mmol cross-linker N, N-methylene bisacrylamide, 2.0 wt% vinyl-modified silk fibroin, and 50 mg Fe3O4@COOH nanoparticles. The morphology structure and the forming process of the acquired HMMIMs were well characterized by POM, SEM, TEM and FT-IR. The HMMIMs were synthesized successfully with a porous structure and large specific surface area. The particle size of the obtained HMMIMs was at 10–20 µm. The obtained microspheres were superparamagnetic and thermo-responsive. The HMMIM adsorption capacity at 25 °C toward bovine serum albumin (BSA) was 89.9 mg/g and the BSA separation factor in BSA/BHb mixtures was 2.12. A good separation efficacy toward BSA was also observed in bovine whole blood. The prepared HMMIM possessed heterogeneous active sites, the BSA adsorption process on HMMIM was chemisorption controlled.

RNA-Polymer Hybrids via Direct and Site-Selective Acylation with the ATRP Initiator and Photoinduced Polymerization.

Combining synthetic polymers with RNA paves the way for creating RNA-based materials with non-canonical functions. We have developed an acylation reagent that allows for direct incorporation of the atom transfer radical polymerization (ATRP) initiator into both short synthetic oligoribonucleotides and natural biomass RNA extracted from torula yeast. The acylation was performed in a quantitative yield. The resulting initiator-functionalized RNAs were used for grafting polymer chains from the RNA by photoinduced ATRP, resulting in RNA-polymer hybrids with narrow molecular weight distributions. The RNA initiator was used for the polymerization of oligo(ethylene oxide) methyl ether methacrylate, poly(ethylene glycol) dimethacrylate, and N-isopropylacrylamide monomers, resulting in RNA bottlebrushes, hydrogels, and stimuli-responsive materials. This approach, readily applicable to both post-synthetic and nature-derived RNA, can be used to engineer the properties of a variety of RNA-based macromolecular hybrids and assemblies providing access to a wide variety of RNA-polymer hybrids.

Temperature-sensitive amphiphilic nanohybrid as rheological modifier of water-in-oil emulsion drilling fluid: Preparation and performance analysis

In our previous study, as a rheological modifier for flat rheology water-based drilling fluid, binary composite temperature-sensitive SiO2 nanohybrid was successfully synthesized and characterized [J. Petrol. Sci. Eng. 219 (2022), 111,096]. The aim of this study was to investigate the flat rheological characteristics of emulsion drilling fluid, a temperature-sensitive amphiphilic ternary composite nanohybrid was prepared via the copolymerization of temperature sensitive polymer monomers N-isopropylacrylamide (NIPAM) and methylallyl alcohol (MAA) in the presence of nano-silica surface-capped by modifier containing double bond (denoted as SiO2-D). The as-prepared PNM/SiO2-D (PNM refers to polymerized NIPAM and MAA) nanohybrid was characterized by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy and transmission electron microscopy. Findings indicate that PNM/SiO2-D nanohybrid has a three-dimensional network structure and a particle size of 20–30 nm. Rheological properties of PNM/SiO2-D nanohybrid in aqueous solution, water-in-oil (W/O) emulsion system and W/O emulsion drilling fluid system were investigated, respectively. And the results revealed that PNM/SiO2-D nanohybrid as a rheological modifier is more sensitive to temperature in the emulsion with a high water-oil ratio, and significantly increase the viscosity of the emulsion system at elevated temperatures. Furthermore, the W/O emulsion drilling fluid with a water-oil ratio of 4:6 exhibits higher modulus values than the one with a water-ratio of 1:9, due to the better suspending capacity of the former for drill cuttings under static conditions, which could ensure the application of emulsion drilling fluid in drilling process.

In situ preparation of PNIPAM biphasic hydrogels

N-isopropylacrylamide (NIPAM) monomer undergoes phase separation in water at very high concentrations, which offers striking opportunities to engineer biphasic hydrogel systems. However, this is a metastable state and NIPAM evolves to crystallize. Besides, the concentration of NIPAM in the lower phase is very small. In this work we show that the aforementioned limitations can be overcome by the incorporation of selected components. Thus, the addition of acrylic acid enables accessing remarkably stable biphasic NIPAM-water systems, as corroborated by DSC (absence of NIPAM crystallization). The addition of a third monomer, diallyldimethylammonium chloride (DDAC), further allows modifying NIPAM partition notably. The phase-distribution of the components for different monomer mixtures was gauged by 1H NMR. Subsequent polymerization leads to the formation of biphasic hydrogels systems in a single step, whose phase morphology and temperature response (swelling response) has been characterized by SEM. This methodology also permits adjusting the crosslinker partition as a function of its nature, which can be used to tune the swelling behaviour of each phase for a certain composition.

Multi-thermo responsive double network composite hydrogel for 3D printing medical hydrogel mask

3D printing of multifunctional hydrogels offers great opportunities for developing innovative biomedical technologies as it can provide custom-designed shapes and structures conformal to arbitrary contours. There have been significant improvements of the 3D printing techniques, but the available printable hydrogel materials limit the progress. Here, we investigated the use of a poloxamer diacrylate (Pluronic P123) to augment the thermo-responsive network composed of poly(N-isopropylacrylamide) and develop a multi-thermoresponsive hydrogel for photopolymerization 3D printing. The hydrogel precursor resin was synthesised to be printable with high-fidelity of fine structures and once cured can form a robust thermo-responsive hydrogel. By utilizing N-isopropyl acrylamide monomer and a Pluronic P123 diacrylate crosslinker as 2 separate thermo-responsive components it was found that the final hydrogel displayed 2 distinct lower critical solution temperature (LCST) switches. This enables the loading of hydrophilic drugs at fridge temperature and improving the strength of the hydrogel at room temperature while still maintaining a drug release at body temperature. The thermo-responsive material properties of this multifunctional hydrogel material system were investigated, showing a significant promise as a medical hydrogel mask. Furthermore, it is demonstrated that it can be printed in sizes large enough to fit and adhere to a human face at 1:1 scale with high dimensional accuracy, as well as its ability to load with hydrophilic drugs.

Designing Multistimuli-Responsive Anisotropic Bilayer Hydrogel Actuators by Integrating LCST Phase Transition and Photochromic Isomerization.

Stimuli-responsive hydrogel actuators have attracted tremendous interest in switches and microrobots. Based on N-isopropylacrylamide (NIPAM) monomers with LCST phase separation and photochromic molecule spiropyran which can respond to ultraviolet light and H+, we develop a novel multistimuli-responsive co-polymer anisotropic bilayer hydrogel, which can undergo complex deformation behavior under environmental stimuli. Diverse bending angles were achieved based on inhomogeneous swelling. By controlling the environmental temperature, the bilayer hydrogels achieved bending angles of 83.4° and -162.4° below and above the critical temperature of PNIPAM. Stimulated by ultraviolet light and H+, the bilayer hydrogels showed bending angles of -19.4° and -17.3°, respectively. In addition, we designed a strategy to enhance the mechanical properties of the hydrogel via double network (DN). The mechanical properties and microscopic Fourier transform infrared (micro-FTIR) spectrum showed that the bilayer hydrogel can be well bonded at the interfaces of such bilayers. This work will inspire the design and fabrication of novel soft actuators with synergistic functions.

PH and Thermoresponsive PNIPAm-co-Polyacrylamide Hydrogel for Dual Stimuli-Responsive Controlled Drug Delivery.

The therapeutic delivery system with dual stimuli-responsiveness has attracted attention for drug delivery to target sites. In this study, we used free radical polymerization to develop a temperature and pH-responsive poly(N-isopropyl acrylamide)-co-poly(acrylamide) (PNIPAM-co-PAAm). PNIPAm-co-PAAm copolymer by reacting with N-isopropyl acrylamide (NIPAm) and acrylamide (Am) monomers. In addition, the synthesized melamine-glutaraldehyde (Mela-Glu) precursor was used as a cross-linker in the production of the melamine cross-linked PNIPAm-co-PAAm copolymer hydrogel (PNIPAm-co-PAAm-Mela HG) system. The temperature-responsive phase transition characteristics of the resulting PNIPAM-co-PAAm-Mela HG systems were determined. Furthermore, the pH-responsive drug release efficiency of curcumin was investigated under various pH and temperature circumstances. Under the combined pH and temperature stimuli (pH 5.0/45 °C), the PNIPAm-co-PAAm-Mela HG demonstrated substantial drug loading (74%), and nearly complete release of the loaded drug was accomplished in 8 h. Furthermore, the cytocompatibility of the PNIPAm-co-PAAm-Mela HG was evaluated on a human liver cancer cell line (HepG2), and the findings demonstrated that the prepared PNIPAm-co-PAAm-Mela HG is biocompatible. As a result, the PNIPAm-co-PAAm-Mela HG system might be used for both pH and temperature-stimuli-responsive drug delivery.

Preparation and action mechanism of temperature sensitive N-isopropylacrylamide/nanosilica hybrid as rheological modifier for water-based drilling fluid

A temperature-sensitive silica nanohybrid with a temperature response at 35 °C was prepared by copolymerization of temperature-sensitive monomer N-isopropylacrylamide (NIPAM) with reactive nanosilica (RNS-D).The rheological properties of the as-prepared NIPAM/nano-SiO2 nanohybrid as the rheological modifier of water-based drilling fluid were tested. Findings demonstrate that NIPAM/nano-SiO2 nanohybrid contributes to increasing the viscosity of the drilling fluid upon elevating temperature, and the drilling fluid fits to the Herschel-Bulkley model. The drilling fluid containing 1.0% (mass fraction) of NIPAM/nano-SiO2 nanohybrid exhibits significant thermally thickening performance at the critical association temperature (Tass) of NIPAM (Tass; 35 °C). In terms of the action mechanism of NIPAM/nano-SiO2 nanohybrid in drilling fluid, the amide group of NIPAM/nano-SiO2 nanohybrid can form hydrogen bond with bentonite, thereby being well adsorbed on the surface and edge of bentonite platelets or even entrapped into the interlay of the bentonite platelets. The resultant cross-linked structure can function to prevent the flocculation of bentonite platelets and increase the viscosity of the drilling fluid. After heating to Tass, the temperature-sensitive polymer molecular chains undergo hydrophilic to hydrophobic transformation and hydrophobic association to form cross-linked three-dimensional network structure and increase the viscosity of the drilling fluid. More importantly, the water-based drilling fluid with 1.0% NIPAM/nano-SiO2 nanohybrid still retains thermally thickening behavior and flat rheology even after being aged at 150 °C. Therefore, the temperature-sensitive NIPAM/nano-SiO2 nanohybrid could be a potential rheological modifier for flat rheology water-based drilling fluid.

Anti-Freezing Nanocomposite Organohydrogels with High Strength and Toughness

Hydrogels based on nanocomposites (NC) structure have acquired a great deal of interest, but they are still limited by relatively low mechanical strength, inevitably losing elasticity when applied below subzero temperatures, due to the formation of ice crystallization. In this study, an anti-freezing and mechanically strong Laponite NC organohydrogel was prepared by a direct solvent replacement strategy of immersing Laponite NC pre-hydrogel into ethylene glycol (EG)/water mixture solution. In the organohydrogel, a part of water molecules was replaced by EG, which inhibited the formation of ice crystallization even at extremely low temperatures. In addition, the formation of hydrogen bonds between Laponite and the monomers of N-isopropylacrylamide (NIPAM) and hydroxyethyl acrylate (HEA) endowed the organohydrogels with high mechanical strength and toughness. The NC organohydrogel can maintain its mechanical flexibility even at −25 °C. The compressive stress, tensile stress, and elongation at the break of N5H5L reached 3871.71 kPa, 137.05 kPa, and 173.39%, respectively, which may be potentially applied as ocean probes in low temperature environment.

Comparative Drug Release Investigations for Diclofenac Sodium Drug (DS) by Chitosan-Based Grafted and Crosslinked Copolymers.

The hydrogels responding to pH synthesized by graft copolymerization only and then concurrent grafting and crosslinking of monomer N-isopropyl acrylamide (NIPAAM) and binary comonomers acrylamide, acrylic acid and acrylonitrile (AAm, AA and AN) onto chitosan support were explored for the percent upload and release study for anti-inflammatory diclofenac sodium drug (DS), w.r.t. time and pH. Diclofenac sodium DS was seized in polymeric matrices by the equilibration process. The crosslinked-graft copolymers showed the highest percent uptake than graft copolymers (without crosslinker) and chitosan itself. The sustainable release of the loaded drug was studied with respect to time at pH 2.2, 7.0, 7.4 and 9.4. Among graft copolymers (without crosslinking), Chit-g-polymer (NIPAAM-co-AA) and Chit-g-polymer (NIPAAM-co-AN) exhibited worthy results for sustainable drug deliverance, whereas Crosslink-Chit-g-polymer (NIPAAM-co-AA) and Crosslink-Chit-g-polymer (NIPAAM-co-AAm) presented the best results for controlled/sustained release of diclofenac sodium DS with 93.86 % and 96.30 % percent release, respectively, in 6 h contact time. Therefore, the grafted and the crosslinked graft copolymers of the chitosan showed excellent delivery devices for the DS with sustainable/prolonged release in response to pH. Drug release kinetics was studied using Fick’s law. The kinetic study revealed that polymeric matrices showed the value of n as n > 1.0, hence drug release took place by non-Fickian diffusion. Hence, the present novel findings showed the multidirectional drug release rate. The morphological changes due to interwoven network structure of the crosslinked are evident by the Scanning electron microscopy (SEM) analysis.

Supramolecular Nanohelix Fabricated by Pillararene-Based Host–Guest System for Chirality Amplification, Transfer, and Circularly Polarized Luminescence in Water

Supramolecular Nanohelix Fabricated by Pillararene-Based Host–Guest System for Chirality Amplification, Transfer, and Circularly Polarized Luminescence in Water

Dual responsive tamarind gum-co-poly(N-isopropyl acrylamide-co-ethylene glycol vinyl ether) hydrogel: A promising device for colon specific anti-cancer drug delivery

In this study, pH and temperature-sensitive tamarind gum (TM)-based hydrogels were synthesized by free radical polymerization using a combination of acrylamide (AM), N-isopropyl acrylamide (NIPAM), and ethylene glycol vinyl ether (EGVE) monomers with bis (2-(methacryloyloxy) ethyl phosphate (BMEP) as a crosslinker (TANEB hydrogel). The prepared TANEB hydrogels were characterized by Fourier transform infrared spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy to confirm the formation of functional group interactions and morphology. 5-Fluorouracil (5-FU) as a model drug was loaded into the TANEB hydrogels. Differential thermal calorimetry and XRD confirmed the molecularly loaded 5-FU into TANEB hydrogels. Swelling studies revealed the dual responsive nature of the TANEB hydrogels. An in vitro drug release study was performed at pH 1.2 and 7.4 and at 25 and 37 °C. The release time of 5-FU from the hydrogels was extended up to 12 h. Also, 5FU encapsulated hydrogels showed remarkable cytotoxicity against human colorectal adenocarcinoma cancer cells (HCT116 cells) along with good cell cycle ability. Thus, the TANEB hydrogel formulations could be used as potential delivery system for anticancer drugs.