N-methylene Bisacrylamide Research Articles

Microcrystalline cellulose and itaconic acid pH sensitive semi interpenetrating network hydrogel for oral insulin delivery

Diabetes mellitus is one of the important causes of death worldwide. Generally, a subcutaneous route is used for insulin administration, but has showed low patient compliance. Extensive research has been conducted to identify molecules capable of delivering insulin orally, for this hydrogel based on microcrystalline cellulose and itaconic acid have been produced and explored. Free radical polymerization as a technique was employed for manufacturing the hydrogels using potassium persulphate as initiator and N, N′-methylene bisacrylamide (NNMBA) as a crosslinker. These pH- sensitive exhibited a swelling capacity of up to 20.38 g/g in distilled water and also revealed stronger swelling in glucose solutions than saline solutions. The pH sensitivity of the hydrogels was confirmed by studying the swelling in different pH solutions. Alkaline solutions showed higher swelling than acidic solutions. SEM established the porous nature, and the structure was examined by FTIR analysis. Thermal degradation was examined using TGA. In vitro release study was done by Bradford assay at 595 nm. The result was further confirmed by in-vivo investigations on male Wistar adult rats and hence is an excellent vehicle for oral insulin administration.

PH and Temperature-Responsive Silk Sericin/N-Isopropyl Acrylamide Interpenetrating Network Gel and Viscose Non-Woven Cross-Linked Composite Dressing

A gel (SNA-Ag) loaded with nanoscale silver particles and a pH-responsive agent was prepared using N-isopropyl acrylamide (NIPAAm) as the first network structure, silk sericin (SS) as the second network structure and reducing agent, alizarin as the pH indicator and co-reducing agent, N, N-methylene bisacrylamide (BIS) as the crosslinking agent, ammonium persulfate (APS) as the initiator and N, N, N, N-tetramethylethylenediamine (TEMED) as co-initiator. To improve the breaking strength of the gel, the temperature and pH-responsive antibacterial (V/SNA-Ag) composite dressing was prepared by crosslinking the SNA-Ag gel with viscose non-woven fabric using glutaraldehyde as the crosslinking agent. Fourier transform infrared spectrometer (FTIR) and scanning electron microscopy (SEM) showed that the SNA-Ag hydrogel was successfully crosslinked with the viscose non-woven fabric. Meanwhile, a gel coating was formed on the fabric, and the coating thickness increased when the crosslinking time was extended. Differential Scanning Calorimetry (DSC) and pH response tests confirmed that the dressing was temperature sensitive, and the Lower Critical Solution Temperature (LCST) of the dressing was about 35 °C. When the pH of the dressing was changed from acidic to alkaline, its color was changed from yellow to purple, indicating that its color presented pH response characteristics. The dressing not only had excellent swelling performance but also had outstanding antibacterial activity; the antibacterial degree for Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was up to 99%. A cytotoxicity test suggested that the survival degree of mouse cells after incubation for 96 h was more than 75%, proving that it was safe and nontoxic. In addition, compared with viscose non-woven fabric, the breaking strength of composite dressing was increased, and the air permeability was decreased. In conclusion, we suggest that V/SNA-Ag composite dressings have great potential for monitoring and treating wounds.

Tannic acid strengthen adhesion of poly(AAm-co-GG) hydrogels for multiple solid surfaces repairing

This study aims to develop bio-compatible mechanically robust, adhesive hydrogels using acrylamide and gellan gum. Tannic acid (TA) and N, N-methylene bisacrylamide (MBA) were used as physical and chemical crosslinkers respectively. Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM) analysis verified the successful synthesis of hydrogels through free radical addition polymerization. The rheological tests, such as frequency sweep, creep recovery, and amplitude sweep were performed to evaluate the effect of TA on the adhesive behavior and viscoelastic properties of hydrogels. Results highlighted the pivotal role of polymer chain interactions in regulating the adhesive behavior. The tannic acid concentration was varied to assess the adhesive performance, higher tannic acid concentration resulted in improved adherence. The adhesion strength order was received as 33.6 > 18 > 7.56 > 6.7 > 6.23 kPa. The prepared adhesive hydrogels performed exceptionally well on wood, cloth, rubber, glass, and ceramics-like materials. Furthermore, the hydrogels were practically found efficient at low as well as at high temperatures. The low price, high efficiency, easy to synthesize, and bio-friendly. etc. characteristics can make these hydrogels to be applied convincingly as adhesives in the future.

Development and validation of LC-MS/MS method for trace analysis of acrylamide, acrylic acid and N, N-methylene bis acrylamide in sandy loam soil

Acrylamide and N, N-methylene bis acrylamide are most commonly used monomer and crosslinker compounds employed in synthesis of super absorbent hydrogels. When applied as soil conditioners, there are apprehensions that these hydrogels degrade over time and thus may release the toxic monomers in the soil. A method was thus developed using Liquid Chromatography tandem mass spectrometry (LC-MS/MS) for the trace level quantification of acrylamide (AD), acrylic acid (AA) and N,N-methylene-bis-acrylamide (MBA) in sandy loam soil amended by two test hydrogels the Pusa Hydrogel and SPG 1118 hydrogel prepared using AD and MBA. The MRM (multiple reaction monitoring) transitions were optimized for both the compounds. Soil samples were extracted using dispersive solid-phase extraction (dSPE) with a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) technique, employing acetonitrile. All analytes were quantified at trace levels within a five-minute run using UHPLC equipped with a C-18 column.Single laboratory validation of the developed method in soil matrix was conducted based on specificity, linearity, sensitivity, accuracy, precision, matrix effect and measurement of uncertainty. LC-MS/MS exhibited a linear response in the concentration range of 0.001 to 1 µg mL−1, with correlation coefficient >+0.99. Acceptable recovery (within 70–120 %) with repeatability (%RSD ≤20 %) was obtained at 0.01 to 1 µg g–1 fortification levels. LOQ (Limit of quantification) of the method for AD, AA and MBA in soil matrix were 0.05, 1 and 0.01 µg g–1, respectively. Both intra-laboratory repeatability and intermediate precision at LOQ suggested well acceptable precise (HorRat≈ 0.3) method for quantification. Matrix enhancement effect was observed in the order: AA>AD>MBA. The Expanded Uncertainty (EU) in soil matrix at LOQ was 21.64 %, 28 % and 19 % for AD, AA and MBA respectively. Groundnut and wheat grown with application of the hydrogels showed no detectable residues of monomers in soil samples (total n = 60) near the root zone at the time of crop harvesting.

Hydrophilic Modification of Polytetrafluoroethylene (PTFE) Capillary Membranes with Chemical Resistance by Constructing Three-Dimensional Hydrophilic Networks.

Polytetrafluoroethylene (PTFE) capillary membranes, known for the great chemical resistance and thermal stability, are commonly used in membrane separation technologies. However, the strong hydrophobic property of PTFE limits its application in water filtration. This study introduces a method whereby acrylamide (AM), N, N-methylene bisacrylamide (MBA), and vinyltriethoxysilane (VTES) undergo free radical copolymerization, followed by the hydrolysis-condensation of silane bonds, resulting in the formation of hydrophilic three-dimensional networks physically intertwined with the PTFE capillary membranes. The modified PTFE capillary membranes prepared through this method exhibit excellent hydrophilic properties, whose water contact angles are decreased by 24.3-61.2%, and increasing pure water flux from 0 to 1732.7-2666.0 L/m2·h. The enhancement in hydrophilicity of the modified PTFE capillary membranes is attributed to the introduction of hydrophilic groups such as amide bonds and siloxane bonds, along with an increase in surface roughness. Moreover, the modified PTFE capillary membranes exhibit chemical resistance, maintaining the hydrophilicity even after immersion in strong acidic (3 wt% HCl), alkaline (3 wt% NaOH), and oxidative (3 wt% NaClO) solutions for 2 weeks. In conclusion, this promising method yields modified PTFE capillary membranes with great hydrophilicity and chemical resistance, presenting substantial potential for applications in the field of water filtration.

Evaluation of Various Types of Alginate Inks for Light-Mediated Extrusion 3D Printing.

Naturally derived biopolymers modifying or combining with other components are excellent candidates to promote the full potential of additive manufacturing in biomedicine, cosmetics, and the food industry. This work aims to develop new photo-cross-linkable alginate-based inks for extrusion 3D printing. Specifically, this work is focused on the effect of the addition of cross-linkers with different chemical structures (polyethylene glycol diacrylate (PEGDA), N,N'-methylenebisacrylamide (NMBA), and acrylic acid (AA)) in the potential printability and physical properties of methacrylated alginate (AlgMe) hydrogels. Although all inks showed maximum photo-curing conversions and gelation times less than 2 min, only those structures printed with the inks incorporating cross-linking agents with flexible and long chain structure (PEGDA and AA) displayed acceptable size accuracy (~0.4-0.5) and printing index (Pr ~1.00). The addition of these cross-linking agents leads to higher Young's moduli (from 1.6 to 2.0-2.6 KPa) in the hydrogels, and their different chemical structures results in variations in their mechanical and rheological properties. However, similar swelling ability (~15 swelling factor), degradability (~45 days 100% weight loss), and cytocompatibility (~100%) were assessed in all the systems, which is of great importance for the final applicability of these hydrogels.

Synthesis and characterization of alginate-polyacrylic acid/multiwalled carbon nanotubes composite with efficient removal for nigrosine dye

ABSTRACT The current study detailed the efficacy of a simply prepared alginate-polyacrylic acid/functionalized multiwalled carbon nanotubes (Alg-PAA/f-MWCNTs) composite for adsorption of nigrosine dye (acid black II) from aqueous environments. Firstly, preparation of the Alg-PAA/f-MWCNTs composite was achieved via gamma radiation-induced template polymerization of AA onto the Alg/f-MWCNTs surface. The maximum grafting efficiency (GE%) of AA onto the surface of Alg/f-MWCNTs was ~ 82% under the optimized conditions: (2.5 wt% Alg, 30 wt% AA, 0.5 wt% f-MWCNTs, 0.6 wt% N,N’-methylenebisacrylamide (NMBA), and irradiation dose ~ 20 kGy). The structural characteristics, thermal features as well as the morphological appearance of the Alg-PAA/f-MWCNTs composite were validated using different analyses including FTIR, TGA, DTA, XRD and SEM. Additionally, the composite exhibited uniform particle size distribution (~150.7 nm), point of zero charge at pH = 6.28, and negative Zeta potentials of a minimum at pH = 2. The adsorption batch experiments showed good adsorption capacity for the nigrosine dye from their aqueous media with adsorption efficiency up to 83% using the batch technique at pH = 2.0 for 420 min. The adsorption of nigrosine dye onto Alg-PAA/f-MWCNTs is favorable thermodynamically, obeying the Freundlich isotherm model and controlled by a chemisorption mechanism. Additionally, the composite showed a good regeneration ability up to five times with almost the same removal of ~80%. The results demonstrated that the Alg-PAA/f-MWCNTs composite could be a promising candidate for the removal of nigrosine dye from industrial aqueous environments.

Evaluation of physiochemical and biomedical properties of psyllium-poly(vinyl phosphonic acid–co-acrylamide)-cl-N,N-methylene bis acrylamide based hydrogels

Present investigation deals with the synthesis of psyllium based copolymeric hydrogels and evaluation of their physiochemical and biomedical properties. These copolymers have been prepared by grafting of poly(vinyl phosphonic acid) (poly (VPA)) and poly(acrylamide) (poly(AAm)) onto psyllium in the presence of crosslinker N,N-methylene bis acrylamide (NNMBA). These copolymers [psyllium-poly(VPA-co-AAm)-cl-NNMBA] were characterized by field emission-scanning electron micrographs (FE-SEM), electron dispersion X-ray analysis (EDAX), Atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), 13C-nuclear magnetic resonance (NMR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA)- differential thermal analysis (DTG). FESEM, AFM and XRD demonstrated heterogeneous morphology with a rough surface and an amorphous nature. Diffusion of ornidazole occurred with a non-Fickian diffusion mechanism, and the release profile data was fitted in the Korsemeyer-Peppas kinetic model. Biochemical analysis of hydrogel properties confirmed the blood-compatible nature during blood-polymer interactions and revealed haemolysis value 3.95 ± 0.05 %. The hydrogels exhibited mucoadhesive character during biomembrane-polymer interactions and demonstrated detachment force = 99.0 ± 0.016 mN. During 2,2-diphenyl-1-picrylhydrazyl reagent (DPPH) assay, free radical scavenging was observed 37.83 ± 3.64 % which illustrated antioxidant properties of hydrogels. Physiological and biomedical properties revealed that these hydrogels could be explored for drug delivery uses.

Porous Poly(2-hydroxyethyl methacrylate) Hydrogel Scaffolds for Tissue Engineering: Influence of Crosslinking Systems and Silk Sericin Concentration on Scaffold Properties.

Tailored porous structures of poly(2-hydroxyethyl methacrylate) (PHEMA) and silk sericin (SS) were used to create porous hydrogel scaffolds using two distinct crosslinking systems. These structures were designed to closely mimic the porous nature of the native extracellular matrix. Conventional free radical polymerization of 2-hydroxyethyl methacrylate (HEMA) was performed in the presence of different concentrations of SS (1.25, 2.50, 5.00% w/v) with two crosslinking systems. A chemical crosslinking system with N'N-methylene bisacrylamide (MBAAm) and a physical crosslinking system with dimethylurea (DMU) were used: C-PHEMA/SS (crosslinked using MBAAm) and C-PHEMA/pC-SS (crosslinked using MBAAm and DMU). The focus of this study was on investigating the impact of these crosslinking methods on various properties of the scaffolds, including pore size, pore characteristics, polymerization time, morphology, molecular interaction, in vitro degradation, thermal properties, and in vitro cytotoxicity. The various crosslinked networks were found to appreciably influence the properties of the scaffolds, especially the pore sizes, in which smaller sizes and higher numbers of pores with high regularity were seen in C-PHEMA/1.25 pC-SS (17 ± 2 μm) than in C-PHEMA/1.25 SS (34 ± 3 μm). Semi-interpenetrating networks were created by crosslinking PHEMA-MBAAm-PHEMA while incorporating free protein molecules of SS within the networks. The additional crosslinking step involving DMU occurred through hydrogen bonding of the -C=O and -N-H groups with the SS, resulting in the simultaneous incorporation of DMU and SS within the PHEMA networks. As a consequence of this process, the scaffold C-PHEMA/pC-SS exhibited smaller pore sizes compared to scaffolds without DMU crosslinking. Moreover, the incorporation of higher loadings of SS led to even smaller pore sizes. Additionally, the gelation time of C-PHEMA/pC-SS was delayed due to the presence of DMU in the crosslinking system. Both porous hydrogel scaffolds, C-PHEMA/pC-SS and PHEMA, were found to be non-cytotoxic to the normal human skin dermal fibroblast cell line (NHDF cells). This promising result indicates that these hydrogel scaffolds have potential for use in tissue engineering applications.

Cydonia oblonga-Seed-Mucilage-Based pH-Sensitive Graft Copolymer for Controlled Drug Delivery-In Vitro and In Vivo Evaluation.

The primary objective of this study was to assess the potential utility of quince seed mucilage as an excipient within a graft copolymer for the development of an oral-controlled drug delivery system. The Cydonia oblonga-mucilage-based graft copolymer was synthesized via a free radical polymerization method, employing potassium per sulfate (KPS) as the initiator and N, N-methylene bisacrylamide (MBA) as the crosslinker. Various concentrations of monomers, namely acrylic acid (AA) and methacrylic acid (MAA), were used in the graft copolymerization process. Metoprolol tartarate was then incorporated into this graft copolymer matrix, and the resultant drug delivery system was subjected to comprehensive characterization using techniques such as Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The swelling behavior of the drug delivery system was evaluated under different pH conditions, and in vitro drug release studies were conducted. Furthermore, pharmacokinetic parameters including the area under the curve (AUC), maximum plasma concentration (Cmax), time to reach Cmax (Tmax), and half-life (t1/2) were determined for metoprolol-loaded hydrogel formulations in rabbit plasma, and these results were compared with those obtained from a commercially available product. The key findings from the study include observations that higher concentrations of acrylic acid (AA) and Cydonia oblonga mucilage (CM) in the graft copolymer enhanced swelling, while the opposite trend was noted at elevated concentrations of methacrylic acid (MAA) and N, N-methylene bisacrylamide (MBA). FTIR analysis confirmed the formation of the graft copolymer and established the compatibility between the drug and the polymer. SEM imaging revealed a porous structure in the prepared formulations. Additionally, the swelling behavior and drug release profiles indicated a pH-sensitive pattern. The pharmacokinetic assessment revealed sustained release patterns of metoprolol from the hydrogel network system. Notably, the drug-loaded formulation exhibited a higher Cmax (156.48 ng/mL) compared to the marketed metoprolol product (96 ng/mL), and the AUC of the hydrogel-loaded metoprolol was 2.3 times greater than that of the marketed formulation. In conclusion, this study underscores the potential of quince seed mucilage as an intelligent material for graft-copolymer-based oral-controlled release drug delivery systems.

Effect of using high molecular weight crosslinker on the physical properties of super porous hydrogel composite

Superporous hydrogel composite is widely utilized and investigated as a gastro retentive drug delivery system. Materials used in Superporous hydrogel formulation have a profound effect on its properties’, N-methylene bisacrylamide is the crosslinker of choice for the preparation of SPH.
 The purpose of this study is to determine if using a new high molecular weight crosslinker such as polyethylene glycol diacrylate will affect the physical characteristics of SPH and drug release behavior. For the preparation of super porous hydrogel polyvinyl alcohol, acrylamide, polyethylene glycol diacrylate 700, N, N-Methylene bisacrylamide, sodium bicarbonate, and tween 20 were used. Trifluoperazine HCl was used as a model drug. The buoyancy, porosity, density, drug release, drug content, swelling ratio, and swelling time were studied and compared. All the physical characteristics and medication release profiles were impacted by changing the formulation parameters. The formula with the best physical qualities had 300 µl of acrylamide (40 percent w/v), 20 mg of polyvinyl alcohol, 200 µl of Tween 20 (v/v), 5 µl of polyethylene glycol diacrylate 700, 45 µl ammonium persulfate, 45 µl TEMED and 50 mg of sodium bicarbonate. Around 80% of the drug was released over the course of 12 hours according to zero order kinetics. By modifying the formulation parameters using polyethylene glycol diacrylate, Superporous hydrogel was successfully manufactured and has the best properties to be employed as a gastro retentive drug delivery system.

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.

Three-dimensional dual-network magnetic conductive hydrogel for the highly sensitive electrochemical detection of ponceau 4R in foods

Synthetic pigment Ponceau 4 R is a commonly used additive in the process of various foods. Due to its potential toxicity to humans, realizing high sensitivity and rapid detection of Ponceau 4 R is extremely important. In this study, we synthesized a novel dual-network magnetic conductive hydrogel (MCHG) via a simple one-pot low temperature stirring method. In MCHG, cationic guar gum (CGG) and β-cyclodextrin (β-CD) formed a primary three-dimensional network cross-linked by N, N-methylene bisacrylamide. A second network was formed in MCHG by CGG, β-CD and magnetite@carboxylate-terminated carbon nanotubes (Fe3O4@COOH-MWCNTs) through hydrogen bonding and electrostatic interactions. Fe3O4@COOH-MWCNTs enhanced cross-linking in the MCHG hydrogel, whilst also boosting the equilibrium adsorption capacity of Ponceau 4 R (61.8 mg g−1), electrical conductivity and electrocatalytic performance. Application of MCHG to a glassy carbon electrode (GCE) created a highly sensitive electrochemical sensor for the detection of Ponceau 4 R. Under optimized testing conditions, the sensor offered a very wide linear range (0.01–200.0 μM) and a low limit of detection (1.8 nM) for Ponceau 4 R. When the sensor was applied to the detection of Ponceau 4 R in spiked honey and liqueur samples, excellent recoveries were achieved (88.2%–107.0%). Furthermore, analyses of commercial biscuit and candy samples using the MCHG/GCE sensor and a national standard ultraviolet spectrophotometry method afforded identical results. Results demonstrate that multifunctional hydrogels show great promise as signal amplification agents in electrochemical detection of target compounds in foods.

Integration of N, P-doped carbon quantum dots with hydrogel as a solid-phase fluorescent probe for adsorption and detection of Fe3+

In this work, a novel nitrogen-phosphorus co-doped carbon quantum dots (N, P-CQDs) hydrogel was developed utilizing the as-synthesized N, P-CQDs and acrylamide (AM) with the existence of ammonium persulfate and N, N′-methylene bisacrylamide (N-MBA). In consistent with pure N, P-CQDs, the N, P-CQDs hydrogel also shows a dramatic fluorescence property with maximum emission wavelength of 440 nm, which can also be quenched after adsorbing iron ions (Fe3+). When the concentration of Fe3+ is 0–6 mmol l−1, a better linear relationship between Fe3+ concentration and the fluorescence intensities can be easily obtained. Additionally, the N, P-CQDs hydrogel exhibits better recyclability. This confirms that the N, P-CQDs hydrogel can be used for adsorbing and detecting Fe3+ in aqueous with on–off–on mode. The fluorescence quenching mainly involves three procedures including the adsorption of Fe3+ by hydrogel, integration of Fe3+ with N, P-CQDs and the transportation of conjugate electrons in N, P-CQDs to the vacant orbits of Fe3+ and the adsorption process follows a pseudo-second-order kinetic model confirmed in the Freundlich isotherm model. In conclusion, this work provides a novel route for synchronously removing and detecting the metal ions in aqueous by integrating N, P-CQDs with hydrogel with better recyclability.

A novel pH-responsive hydrogel system based on Prunus armeniaca gum and acrylic acid: Preparation and evaluation as a potential candidate for controlled drug delivery

pH-responsive hydrogels have become effective and attractive materials for the controlled release of drugs at pre-determined destinations. In the present study, a novel hydrogel system based on Prunus armeniaca gum (PAG) and acrylic acid (AA) was prepared by a free radical mechanism using N, N-methylene bisacrylamide (MBA) as cross-linker and potassium persulfate (KPS) as initiator. A series of hydrogels varying PAG, AA, and MBA concentration was developed to determine the impact of these components. Formulated hydrogels were characterized for pH-responsive swelling, drug release, gel content, and porosity. Structural analysis was performed by FTIR, XRD, and SEM analysis. TGA study was applied to assess thermal stability. Oral acute toxicity and in vivo drug release were performed in rabbits. Hydrogels exhibited pH-dependent swelling and drug release. Swelling, drug loading and release, and porosity increased by increasing PAG and AA concentration while decreased by increasing MBA. The gel content of formulations was increased by increasing all three components. FTIR studies confirmed the development of copolymeric networks and the loading of drug. XRD studies revealed that hydrogels were amorphous, and the crystalline drug was changed into an amorphous form during loading. TGA results indicated that hydrogels were stable up to 600 °C. Acute oral toxicity results confirm that hydrogels were nontoxic up to a dose of 2 g/kg body weight in rabbits. The pharmacokinetic evaluation revealed that hydrogels prolonged the availability of the drug and the peak plasma concentration of the drug was obtained in 6 h as compared to the oral solution of the drug. Tramadol hydrochloride (THC) was used as a model drug. Hence, pH-responsive swelling and release, nontoxic nature and improved pharmacokinetics support that PAG-based hydrogels may be considered as potential controlled-release polymeric carriers.

Polyacrylic acid/ polyvinylpyrrolidone hydrogel wound dressing containing zinc oxide nanoparticles promote wound healing in a rat model of excision injury

Developing and designing efficient wound dressings have gained increasing attention and shown beneficial results in improved wound healing effects. This study was conducted to improve wound healing properties and introduce a novel potential wound dressing. A novel hydrogel based on polyvinylpyrrolidone/poly acrylic acid containing Zinc oxide nanoparticles was prepared as an antibacterial wound dressing and examined in a rat excisional wound model. This hydrogel prepared by free radical polymerization using potassium persulfate (KPS) as an initiator, N, N-methylene bisacrylamide (MBA) as a cross-linker, poly acrylic acid (PAA) as a monomer in the presence of polyvinylpyrrolidone (PVP) and Zinc oxide nanoparticles (ZnO NPs). Analyses such as Scanning Electron Microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), and Thermal gravimetric analysis (TGA) were used to study morphology structure. After choosing the optimal sample, in vivo characterization of excisional wound injury on a rat model was done. The healing rate and histological analysis were calculated and compared among the groups. The therapeutic potential of the PAA-PVP-ZnO-%2 was investigated in a rat model of excisional injury compared to the control group. Results showed that the polyacrylic acid/polyvinylpyrrolidone hydrogel wound dressing containing zinc oxide nanoparticles accelerated wound contraction, had antibacterial effects, and promoted wound healing compared to other groups.

A practical approach using a novel porous photocatalyst/hydrogel composite for wastewater treatment

In this study, a practical use-suited highly porous zinc oxide/polyacrylamide hydrogel composite photocatalyst (ZnO/PAM) was successfully synthesized by varying the precursor ratio upon photoinitiated polymerization of acrylamide (AM), N,N-methylenebisacrylamide (NMBA) and zinc oxide (ZnO). The photocatalytic treatment of real wastewater was investigated. The results revealed that porous ZnO/PAM was effective for the removal of color, BOD and COD in the Mae Kha canal and industrial wastewater. Furthermore, it showed good long-term stability and recycling performance, as the degradation efficiency remained up to 81.55% for MB and 75.4% for MO after 50 degradation cycles. Based on the results, the highly porous zinc oxide/polyacrylamide hydrogel composite prepared by using a specific precursor ratio has good potential for use in real wastewater treatment. Separation of the porous hydrogel from wastewater can be achieved by the preparation of a floatable porous ZnO/PAM hydrogel.

Using a Smartphone-Based Colorimetric Device with Molecularly Imprinted Polymer for the Quantification of Tartrazine in Soda Drinks.

The present study reports the development and application of a rapid, low-cost in-situ method for the quantification of tartrazine in carbonated beverages using a smartphone-based colorimetric device with molecularly imprinted polymer (MIP). The MIP was synthesized using the free radical precipitation method with acrylamide (AC) as the functional monomer, N,N'-methylenebisacrylamide (NMBA) as the cross linker, and potassium persulfate (KPS) as radical initiator. The smartphone (RadesPhone)-operated rapid analysis device proposed in this study has dimensions of 10 × 10 × 15 cm and is illuminated internally by light emitting diode (LED) lights with intensity of 170 lux. The analytical methodology involved the use of a smartphone camera to capture images of MIP at various tartrazine concentrations, and the subsequent application of the Image-J software to calculate the red, green, blue (RGB) color values and hue, saturation, value (HSV) values from these images. A multivariate calibration analysis of tartrazine in the range of 0 to 30 mg/L was performed, and the optimum working range was determined to be 0 to 20 mg/L using five principal components and a limit of detection (LOD) of 1.2 mg/L was obtained. Repeatability analysis of tartrazine solutions with concentrations of 4, 8, and 15 mg/L (n = 10) showed a coefficient of variation (% RSD) of less than 6%. The proposed technique was applied to the analysis of five Peruvian soda drinks and the results were compared with the UHPLC reference method. The proposed technique showed a relative error between 6% and 16% and % RSD lower than 6.3%. The results of this study demonstrate that the smartphone-based device is a suitable analytical tool that offers an on-site, cost-effective, and rapid alternative for the quantification of tartrazine in soda drinks. This color analysis device can be used in other molecularly imprinted polymer systems and offers a wide range of possibilities for the detection and quantification of compounds in various industrial and environmental matrices that generate a color change in the MIP matrix.

Synthesis, Characterisation and Comparative Study of Hydrogel and Nanogels of Psyllium

Natural polysaccharides are being explored as the matrices for attaining speciality materials for pharmaceutical, medicinal and environmental applications via chemical modification such as grafting. Psyllium polysaccharide-based hydrogels and nanogels have potential biomedical and water purification applications due to their advantageous properties such as stimulus responsiveness, biocompatibility, target drug delivery and stability. The present study aims to synthesise hydrogel and nanogels of psyllium and attain comparative data for the two to undermine their potential applications. Psyllium– cl –N,N–MBAm–poly(AAm) hydrogel (Psy-MBAm-AAm – hg) and Psyllium– cl –N,N–MBAm–poly(AAm) nanogel (Psy-MBAm-AAm – ng) were synthesised by grafting acrylamide (AAm) onto psyllium using ammonium persulphate (APS) as a free radical initiator in a redox system where N, N-methylene bisacrylamide acted as a crosslinker. The comparative study of synthesised gels was carried out by studying swelling characteristics at acidic and basic pH (7 and 4) and at varied temperatures for both matrices. The synthesised hydrogel and nanogels were subjected to characterisation by Fourier transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), and Zeta Potential Analysis to get evidence for successful synthesis and nanogel formation.

Fabrication of a bifunctionalized photocatalyst/hydrogel composite for the degradation of particulate matter (PM)-bound polycyclic aromatic hydrocarbons(PAHs)

In this study, a bifunctionalized photocatalyst/hydrogel composite material (ZnO/PAM-PVA) was fabricated on aluminum wire mesh via the coinitiators ammonium persulfate (APS) and a self-initiated zinc oxide (ZnO) photocatalyst. Acrylamide (AM) was blended with polyvinyl alcohol (PVA), N,N-methylene-bis-acrylamide (NMBA) was used as a crosslinker, and ZnO was used as a photocatalyst. After fabrication, the aluminum wire mesh presented two different appearances depending on the major initiator component on each side. The photocatalytic activity of the prepared hydrogel composite material under sunlight irradiation was examined for the degradation of polycyclic aromatic hydrocarbons (PAHs) in particulate matter (PM) from various smoke sources. The results revealed that the ZnO/PAM-PVA hydrogel composite material was effective for the removal of PAHs. After 2 h of sunlight irradiation, the amounts of individual PAHs in PM samples significantly decreased. Therefore, the ZnO/PAM-PVA hydrogel composite could be applied as a promising photocatalytic material for air purification.