Methylene Bisacrylamide Research Articles

High‐strength, ultrastretchable hydrophobic association hydrogel reinforced by tailored modified carboxymethyl cellulose

AbstractA new pathway to construct high‐strength, ultrastretchable hydrogels based on tailored modified carboxymethyl cellulose (TMCMC)and hydrophobic association(HPA) system was investigated. TMCMC was prepared from degradation of carboxymethyl cellulose (CMC)/N,N′‐methylene bisacrylamide (MBA) chemical cross‐linked hydrogels. The residual double bonds of TMCMC, confirmed by 1H‐NMR and FTIR analysis, reacted with acrylamide in HPA to form TMCMC/HPA hydrogels, and the homogeneous and fine spatial network structure of TMCMC/HPA hydrogel could be observed by scanning electron microscopy. Rheological analysis revealed that the coexistence of physical and chemical crosslinking in TMCMC/HPA hydrogels. Further studies showed that TMCMC/HPA hydrogel with MBA content of 0.5 wt% has outstanding mechanical properties, and its fracture stress, elongation and tensile strength reach 1.17 MPa, 3717.05% and 15.68 MJ·m−3, respectively. Moreover, the hydrogel displayed good swelling resistance and stable strain electrical signal response.

Preparation of Isopropyl Acrylamide Grafted Chitosan and Carbon Bionanocomposites for Adsorption of Lead Ion and Methylene Blue.

Wastewater, which is rich with heavy elements, dyes, and pesticides, represents one of the most important environmental pollutants. Thus, it has been significant to fabricate environmentally friendly polymers with high adsorption ability for those pollutants. Herein, crosslinked chitosan (C-Cs) was prepared using isopropyl acrylamide and methylene bisacrylamide. Carbon nanoparticles (C-NPs) were also obtained by the treatment of the agricultural wastes, which was used with C-Cs to prepare C-Cs/C-NPs nanocomposite (C-Cs/C-NC). Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and transmission electron microscope (TEM) were used to investigate the prepared adsorbent. C-Cs, C-NPs, and C-Cs/C-NC were used in water treatment for the adsorption of lead ions (Pb+2) and methylene blue (MB). The adsorption process occurred by the prepared samples was investigated under different conditions, including contact time, as well as different doses and concentrations of adsorbents. The findings exhibited that the adsorption of Pb+2 and MB by C-Cs/C-NC was higher than C-Cs and C-NPs. In addition, the kinetic and isotherm models were studied, where the results showed that the adsorption of Pb+2 and MB by various adsorbents obeys pseudo-second-order and Langmuir isotherms, respectively.

Drug release and thermal properties of magnetic cobalt ferrite (CoFe2O4) nanocomposite hydrogels based on poly(acrylic acid-g-N-isopropyl acrylamide) grafted onto gum ghatti

The aim of this study was to better understand the underlying drug release characteristics from Gg-cl-poly(NIPA-co-AA)/CoFe2O4 hydrogel containing metformin hydrochloride as model drug. Nanocomposite's hydrogel of gum ghatti free radical polymerization is used for the controlled release of metformin hydrogen chloride. Gum ghatti and CoFe2O4 nanoparticle dispersion were grafted by acrylic acid and N-isopropylacrylamide, employing graft copolymerization in the presence of N, N′–methylene-bis-acrylamide (MBA) as cross linker, and ammonium persulfate (APS) as initiator. The synthesized nanocomposites hydrogel was characterized using FTIR, SEM, TGA and DSC. Drugs were all released through diffusion in the hydrated matrix and polymer relaxation, irrespective of the drug solubility. In vitro drug release studies, at different pH values of pH = 4.0, 7.4 and 9.2 was employed. Drug release was influenced by the change of pH. The pH of 7.4 was considered as the optimized pH for maximum drug release. The nanocomposites hydrogel was loaded with metformin hydrochloride drug (100 mg) which is an antidiabetic drug to investigate the release profiles in PBS (pH 7.4). The effects of polymer level and initial drug loading on release depended on drug properties. Different models were studied for release kinetic studies which showed that the zero-order model suggested the best kinetics release studies in PBS (pH- 7.4) and showed sustained release. The kinetics of drug release were discovered to fit the Korsmeyer-Peppas model with n > 1, indicating a specific case II transport mechanism.

Novel Method of Oil/Water Separation Using Composite of Polymethylacrylamide Hydrogel-Coated Metal Mesh

Different compositions of hydrogels composed of mathacrylamide homopolymer (60 and 90% of PMAM) were prepared using the free radical polymerization technique, with and without methylene bisacrylamide as crosslinker (0 and 3%). Several parameters and properties were studied to evaluate their performance as oil/water separators. Many parameters are used, such as residual oil in water, water recovery, separation time, hydrogels coated percentages, swelling parameters, mechanical properties, microscopic and photographic images, and scanning electron microscopy. The results showed that water recovery (87-97), Separation efficiency (96.2-99.6 %), separation time (6-9.5 min.), hydrogels coated percentages (18-23 %), water content (70-97 %), and tensile test (63-90 MPa). The effect of polymer crosslinking density, mesh pore size, and polymer composition on the parameters and properties mentioned above were also studied. The results showed that the separation efficiency of 1000 micron mesh composite is better than 500-micron mesh composites.

Adsorptive removal of cationic dye by synthesized sustainable xanthan gum-g p(AMPS-co-AAm) hydrogel from aqueous media: Optimization by RSM-CCD model

This research aims to treat toxic methylene blue (MB) dye from contaminated water due to its harmful effects on human health and the environment. For this purpose, xanthan gum-based hydrogel was prepared by grafting acrylamide (AAm) and 2-acrylamido-2-methly propane sulfonic acid (AMPS) onto xanthan gum (XG) with methylene bis acrylamide (MBA) as a crosslinking agent. With the introduction of sulfonate and carboxylate groups, the XG molecules were rearranged with better regularity, and based on rheology analysis; higher mechanical stability was approved. The central composite design (CCD) experimental design was used to evaluate the main and interaction effects of the independent hydrogel composition parameters (AMPS, AAm, and MBA concentration) and to derive a model from predicting optimization of the hydrogel composition to remove methylene blue (MB) dye. Accordingly, the concentrations of AAm (6 wt%), AMPS (4.09 wt%), and MBA (0.12 wt%) was found to be the optimum amount for the prepared pH-sensitive adsorbent to remove 98.85% of MB from an aqueous solution using CCD-RSM optimization. The fabrication of hydrogel and its interaction with monomers was specified by FTIR, TGA, rheology, FESEM, and ESEM techniques. The high porosity of hydrogel when swelled was confirmed based on ESEM images. A pseudo-first-order model and Langmuir isotherms best described the adsorption kinetics and adsorption equilibrium, respectively. The maximum equilibrium adsorption capacity of MB was obtained at 384.62 mg/g. The thermodynamic parameters indicated that the adsorption is endothermic and a process that increases irregularity. The hydrogel was regenerated for up to five cycles without significant reduction.

Poly(N-vinylpyrrolidone)-Laponite XLG Nanocomposite Hydrogels: Characterization, Properties and Comparison with Divinyl Monomer-Crosslinked Hydrogels.

The present work investigates, for the first time, the synthesis and properties of some nanocomposite (NC) hydrogels obtained by the aqueous solution free radical polymerization of N-vinylpyrrolidone (NVP) in the presence of Laponite XLG (XLG) as a crosslinker, in comparison with the corresponding hydrogels prepared by using two conventional crosslinking divinyl monomers: N,N′-methylenebisacrylamide (MBA) and tri(ethylene glycol) divinyl ether (DVE). The structure and properties of the hydrogels were studied by FTIR, TEM, XRD, SEM, swelling and rheological and compressive mechanical measurements. The results showed that DVE and XLG are much better crosslinking agents for the synthesis of PNVP hydrogels than MBA, leading to larger gel fractions and more homogeneous network hydrogels. The hydrogels crosslinked by either DVE or XLG displayed comparable viscoelastic and compressive mechanical properties under the experimental conditions employed. The properties of the XLG-crosslinked hydrogels steadily improved as the clay content increased. The addition of XLG as a second crosslinker together with a divinyl monomer strongly enhanced the material properties in comparison with the hydrogels crosslinked by only one of the crosslinkers involved. The FTIR analyses suggested that the crosslinking of the NC hydrogels was the result of two different interactions occurring between the clay platelets and the PNVP chains. Laponite XLG displayed a uniform distribution within the NC hydrogels, the clay being mostly exfoliated. However, a small number of platelet agglomerations were still present. The PNVP hydrogels described here may find applications for water purification and in the biomedical field as drug delivery systems or wound dressings.

Surface molecular imprinted membranes as a “gate” for selective transdermal release of chiral drug amlodipine

Amlodipine is a commonly used and effective drug for the treatment of hypertension. This work investigates imprinted membranes with functional molecular recognition properties prepared via the surface molecular imprinted technology. The surface molecular imprinted membrane are synthesized by taking (S)-amlodipine (S-ADP) as the template molecule, methacrylic acid (MAA) as the functional monomer, and N, N′-methylenebisacrylamide (MBA) as the cross-linker in the present of a surface-initiating system of –OH/Ce4+ constituted by the hydroxyl on the surface of basilemma polyvinyl alcohol (PVA) and ammonium cerium sulfate dissolved in solvent.The imprinted layer is grafted onto the PVA membranes followed by the removal of the S-ADP template molecule, obtaining the S-ADP surface molecular imprinted membranes (S-ADP-SMIMs). The membrane is characterized by Fourier transform infrared reflection (FTIR), and scanning electron microscopy (SEM),13C Nuclear Magnetic Resonance spectroscopy (13C NMR) and X-ray photoelectron spectroscopy (XPS). The ability of enantioseparation and selective permeability of S-ADP-SMIMs is studies. As a result, the selectivity coefficient is 4.6 and the optical purity of adsorption liquid gets up to 80% for S-ADP-SMIMs. However, the non-surface molecular imprinted membrane (NSMIM) shows no selectivity. And the results of in vitro release experiments reveal that the cumulative amounts released of S-ADP and R-amlodipine (R-ADP) is 1459.01 μg cm−2 and 106.21 μg cm−2, respectively. In the skin permeation experiments, the optimal drug concentration is 4.0 mg/mL, Carbopol is determined 0.9% and 1% oleic acid is acted as excellent permeation enhancer. The cumulative amount transported reaches 1719.68 μg cm−2 for S-ADP, while a lower value of 228.17 μg cm−2 is measured for R-ADP. These results strongly suggest the formation of imprinted cavities, which offer selectivity for the transport of S-ADP. So, the imprinted membrane is universal for other chiral drugs. It makes it possible to selectively delivery dominant isomers exactly and efficiently.

One-Pot Synthesis of Pt Nanobowls Assembled from Ultrafine Nanoparticles for Methanol Oxidation Reaction.

Simultaneously engineering a bowl-like and ultrafine nano-size structure offers an attractive route to not only increase the utilization efficiency of noble metals, the specific surface areas and the availability of active sites, but also boost the structural robustness and long-term stability. However, a great challenge remains in terms of the methods of synthesis. Herein, we report a facile one-pot hydrothermal method for the preparation of hollow porous Pt nanobowls (NBs) assembled from ultrafine particles. N,N′-methylenebisacrylamide (MBAA) acts as a structure-directing agent that forms a self-template with Pt ions and drives the nucleation and assembly of Pt metals, resulting in the fabrication of Pt NBs from ultrafine particles. By virtue of their unique structure and morphology, the optimized Pt NBs exhibited enhanced electrocatalytic methanol oxidation reaction (MOR) activity with 3.1-fold greater mass activity and 2.6-fold greater specific activities compared with those of commercial Pt black catalysts, as well as excellent stability and anti-poisoning ability.

Preparation of pH-Responsive Hydrogels Based on Chondroitin Sulfate/Alginate for Oral Drug Delivery.

This study investigates pH-sensitive hydrogels based on biocompatible, biodegradable polysaccharides and natural polymers such as chondroitin sulfate and alginate in combination with synthetic monomer such as acrylic acid, as controlled drug carriers. Investigations were conducted for chondroitin sulfate/alginate-graft-poly(acrylic acid) hydrogel in various mixing ratios of chondroitin sulfate, alginate and acrylic acid in the presence of ammonium persulfate and N′,N′-Methylene bisacrylamide. Crosslinking and loading of drug were confirmed by Fourier transform infrared spectroscopy. Thermal stability of both polymers was enhanced after crosslinking as indicated by thermogravimetric analysis and differential scanning calorimeter thermogram of developed hydrogel. Similarly, surface morphology was evaluated by scanning electron microscopy, whereas crystallinity of the polymers and developed hydrogel was investigated by powder X-ray diffraction. Furthermore, swelling and drug-release studies were investigated in acidic and basic medium of pH 1.2 and 7.4 at 37 °C, respectively. Maximum swelling and drug release were detected at pH 7.4 as compared to pH 1.2. Increased incorporation of hydrogel contents led to an increase in porosity, drug loading, and gel fraction while a reduction in sol fraction was seen. The polymer volume fraction was found to be low at pH 7.4 compared to pH 1.2, indicating a prominent and greater swelling of the prepared hydrogels at pH 7.4. Likewise, a biodegradation study revealed a slow degradation rate of the developed hydrogel. Hence, we can conclude from the results that a fabricated system of hydrogel could be used as a suitable carrier for the controlled delivery of ketorolac tromethamine.

Self-assembled Cr2O3@nanogel/Au nanozymes to simulate peroxidase activity as a H2O2 sensor

The low temperature solvothermal method synthesized Cr2O3 NPs has not only peroxidase activity, but also oxidase activity. Then, the oxidase activity of Cr2O3 NPs is effectively shielded by nanogel immobilization using three monomers acrylamide, NIPAAM (N-isopropylacrylamide) and MBA (N,N′-methylene bisacrylamide) in HEPES (4-(2-hydroxyerhyl)piperazine-1-erhanesulfonic acid) buffer. Ultimately, the enzymatic activity of Cr2O3@nanogel/Au is significantly enhanced after doping Au NPs by SERS (Surface Enhanced Raman Spectroscopy) evaluation. A SERS strategy was proposed for the detection of H2O2 by Cr2O3@nanogel/Au. The linear range was 10−8 mol·L−1-10−1 mol·L−1.

Novel Cacao oil-based organo-hydrogels to detect carcinoma antigen 125 in serum medium; synthesis, characterization, and electrochemical measurements

In present study, cacao oil-based organo-hydrogels (OHCOs) are synthesized to detect carcinoma antigen 125 (CA-125) in serum medium with electrochemical methods such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). OHCOs are prepared by the free radical polymerization reaction with agar, glycerol, and distinct ratios of cacao oil with glutaraldehyde (GA) crosslinker or methylene bisacrylamide (MBA) crosslinker. OHCOs are characterized via Fourier Transform Infrared Spectroscopy (FT-IR), in different solvent environments and pHs. Electrochemical measurements are performed on OHCOs at the presence and absence of CA-125 antigen in serum medium. For the electrochemical sensor, two distinct linear ranges are determined as 0.00083–41.5 U/mL and 83.0–2075 U/mL. LOD and LOQ values are found as 0.34 μU/mL and 1.01 μU/mL, respectively. These results clearly show that OHCOs is a promising sensor material for the determination of CA-125 in human serum, sensitively.

Ultra-fast pH determination with a new colorimetric pH-sensing hydrogel for biomedical and environmental applications

In this study that demonstrates many firsts in the literature, the acrylate derivative (BTBm) of bromothymol blue, retaining its indicator feature, was synthesized as a monomer via using an organic indicator bromothymol blue (BTB). After the structural characterization of BTBm synthesized by ourselves for the first time, copolymeric hydrogel systems were formed with three different commercial monomers in cationic (3-Acrylamidopropyl-trimethylammonium chloride / APTMACl), anionic (3-Sulfopropyl acrylate potassium salt / SPA) and neutral (acrylamide / AA) structures. Structural characterization of BTBm-based hydrogels, which was successfully synthesized by using a 0.5% methylene bisacrylamide (MBA) crosslinker, was elucidated by FT-IR spectroscopy. The morphological structures and elemental compositions of the hydrogels were examined by SEM and EDX elemental mapping analyses. The color changes of BTBm-based hydrogels, which are intended to be used as colorimetric pH sensors, were examined in different pH environments both with naked-eye and by using a UV–Vis spectrophotometer. It has been observed that APTMACl-BTBm hydrogel can be a more beneficial colorimetric pH sensor material than other BTBm-based hydrogels in terms of its ability to respond to pH changes in a wide color range, short response time, and mechanical strength performance.

Preparation and in-vitro characterization of 5-aminosalicylic acid loaded hydrogels for colon specific delivery

The aim of the current investigation was to prepare and characterize the novel pH-sensitive hydrogels of pluronic F127 and sodium polystyrene sulfonate for the controlled delivery of 5-aminosalicylic acid to colon. Pluronic F127 and sodium polystyrene sulfonate were crosslinked with acrylic acid by N,N′-Methylene bisacrylamide. Various studies including porosity, drug loading, swelling, and drug release were performed for the fabricated hydrogels. Greater swelling and drug release were observed at high pH 7.4 as compared to pH 4.6 and 1.2, thus depicted pH-sensitive nature of developed hydrogel. Characterizations such as Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), X-ray diffraction (XRD) analysis, and scanning electron microscopy (SEM), were performed in order to evaluate the crosslinking, thermal stability, crystallinity, and surface morphology of the fabricated hydrogel, respectively. The toxicity of the developed drug carrier system was investigated by the HET-CAM test and revealed no toxic effects on the chorioallantoic membrane of the chicken egg. Conclusively, the fabricated hydrogel could be applied as a potential alternate to conventional dosage forms for controlled release of 5-aminosalicylic acid for prolonged period of time.

In-vitro and in-vivo evaluation of biocompatible polymeric microgels for pH- driven delivery of Ketorolac tromethamine

The aim of the current study was to prepare glutamic acid crosslinked poly(itaconic acid/methacrylic acid) microgels for pH-responsive delivery of ketorolac tromethamine, using aqueous free radical polymerization technique. The polymerization of polymer with monomers was carried out by a crosslinking agent N′, N′-methylene bisacrylamide in the presence of initiator ammonium persulfate. The prepared microgels were characterized for structure, surface morphology, thermal stability, and crystallinity. Similarly, studies such as sol-gel analysis, drug loading, and polymer volume fraction were performed for the fabricated microgels. The pH-sensitivity of the developed microgels was investigated at three different pH values i.e., pH 1.2, 4.6, and 7.4 by swelling and in-vitro drug release studies. Maximum swelling and drug release were found at pH 7.4 as compared to pH 1.2 and 4.6, which indicated the pH-sensitive nature of the prepared microgels. The toxicity of the prepared microgels was evaluated by cell line and HET-CAM test, which demonstrated no toxic effect of the prepared microgels. In-vivo study was carried out on rabbits and high plasma concentration was reported for the drug loaded microgels as compared to drug solution and commercial product Keten. Hence, the prepared microgel system could be employed as an excellent carrier for the controlled drug delivery system.

Attitudes and Practices regarding Nosocomial Infection among a Sample of Para-medical staff in Al-Najaf Governorate

>Hydrogels are considered one of the most important polymers, with very low economic costs for treating dyes from an aqueous solution. In this study, sodium alginate (SA), a kind of polysaccharide, and acrylic acid is an organic compound, N’-Methylene-bis-acrylamide (MBA) as a cross-linked agent, were used to prepare the hydrogel by free radical method. Studies have shown that sodium lignite-based nano-hydrogel is environmentally friendly, more cost-effective and highly efficient in remove dye in aqueous solution. The hydrogel adsorption characteristic was analyzed via scanning electron microscope (SEM). The data appear that the surface contains many pores and has a sponge-like structure. also the results showed that the hydrogel is the XRD of (SA-g-PAAc) a wide band at 2θ = 20.52° within the calculated d = 4.21A°. Study isotherm adsorption the highest (R²=0.9903) related to the isotherm Freundlich and Kinetic model the adsorption process of Rose Bengal dye on the SA-g-PAAc hydrogel follows a second model.

Synthesis and Characterization of Ibuprofen Delivery System Based on β-cyclodextrin/Itaconic Acid Copolymer

This study aims at preparation and characterization of drug delivery system based on grafted beta-cyclodextrin (β-CD) with itaconic acid (IA) using free-radical copolymerization technique, in the presence of N, N'-methylene bisacrylamide (BIS) and ammonium persulphate (APS) as a crosslinker and an initiator, respectively. The obtained copolymer (CD-PIA) was characterized using Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray diffraction patterns (XRD), transmission and scanning electron microscopes (TEM and SEM). Ibuprofen (IBU), as an anti-inflammatory drug model, was loaded during the preparation. The kinetic of the copolymerization was investigated in terms of grafting yield (GY %), grafting efficiency (GE %) and monomer conversion (%). Moreover, in vitro IBU release and kinetic of released using the different mathematical models (0-order, first-order and Higushi) were carried out in simulated gastric and intestinal fluids (SGF and SIF at pH 1.2 and 7.4, respectively) at 37 °. The results proved the successful preparation of the target copolymer with irregular spherical-like shape and particle size around 14 - 27.7 nm. After IBU loading, the copolymer exhibited thermal stability with crystalline nature. Also, the study showed that the synthesized copolymer, especially which high IA content is controlled the release of IBU after 4 h. Besides, it could be used as a potential IBU delivery system with sustained-release followed the first-order kinetic over 24 h.
 HIGHLIGHTS
 
 The nanogels drug carriers used for nonsteroidal anti-inflammatory drugs to overcome the unfavorable release in the stomach due to unforeseen pH alterations
 The polymeric grafted β-CD derivatives using IA represent a unique class of the host materials with tunable inclusion properties and high affinity for Ibuprofen release
 In vitro kinetic of IBU released showed the best fit with first-order model
 
 GRAPHICAL ABSTRACT

Semi-interpenetrating network based on xanthan gum-cl-2-(N-morpholinoethyl methacrylate)/titanium oxide for the single and binary removal of cationic dyes from water

In the present study, semi-interpenetrating polymer networks (semi-IPNs) were synthesized based on xanthan gum (XG)-cl-2-(N-morpholinoethyl methacrylate) (MEMA)/titanium dioxide (TiO2) in the presence of N, N` methylene bisacrylamide (MBAAm), as the cross-linking agent. After that, the semi-IPN hydrogel was used to adsorb Methylene Blue (MB+) and Crystal Violet (CV+) from single and two-component adsorption systems. The optimal pH for efficient dye adsorption in aqueous solutions has been determined to be 8 for CV+ and 11 for MB+, respectively. The presence of polar oxygen-containing functional groups such as OH, CO, C-O-C, COOH, and others has been noticed to be the primary driving force in dye adsorption.Equilibrium data from a single process fitted very well to the Freundlich and Dubinin–Radushkevich models (R2 = 0.997 and 0.99) for MB+ and CV+, respectively. In a binary system, CV+ removed more than MB+, and both dyes demonstrated synergism during the adsorption of CV+/MB+ solutions. The dye removal efficiency of the adsorbent was found to be quite good even after the fourth adsorption-desorption cycle. In the treatment of multi-component contaminated water, XG-cl-poly (MEMA)/TiO2 might be a beneficial and reusable adsorbent.

Preparation of poly(acrylic acid)/tricalcium phosphate nanoparticles scaffold: Characterization and releasing UC-MSCs derived exosomes for bone differentiation.

This study focused on preparing a multiscale three-dimensional (3D) scaffold using tricalcium phosphate nanoparticles (triCaPNPs) in a substrate of poly(acrylic acid) (PAA) polymer for controlled release of exosomes in bone tissue engineering. A scaffold was fabricated with a material mixture containing acrylic acid (AA) monomer, N,N'-methylenebisacrylamide (MBAA), ammonium persulfate (APS), sodium bicarbonate (SBC), and triCaPNPs called composite scaffold (PAA/triCaPNPs) via cross-linking and freeze-drying methods. The synthesis process was easy and without complex multi-steps. Through mimicking the hybrid (organic-inorganic) structure of the bone matrix, we here chose triCaPNPs for incorporation into the PAA polymer. After assessing the physicochemical properties of the scaffold, the interaction of the scaffold with human umbilical cord mesenchymal stem cells (UC-MSCs) such as attachment, proliferation, and differentiation to osteoblast cells was evaluated. In addition, we used DiI-labeled exosomes to verify the exosome entrapment and release from the scaffold. The polymerization reaction of 3D scaffold was successful. Based on results of physicochemical properties, the presence of nanoparticles in the composite scaffold enhanced the mechanical stiffness, boosted the porosity with a larger pore size range, and offered better hydrophilicity, all of which would contribute to greater cell penetration, proliferation, and then better bone differentiation. In addition, our results indicated that our scaffold could take up and release exosomes, where the exosomes released from it could significantly enhance the osteogenic commitment of UC-MSCs. The current research is the first study fabricating a multiscale scaffold using triCaPNPs in the substrate of PPA polymer using a cross-linker and freeze-drying process. This scaffold could mimic the nanoscale structure and chemical combination of native bone minerals. In addition, our results suggest that the PAA/triCaPNPs scaffold could be beneficial to achieve controlled exosome release for exosome-based therapy in bone tissue engineering.

Polymorphic synthesis and structural characterization of NaSbO3 prepared by sol–gel acrylamide polymerization

The formation of the NaSbO3 polymorphic compound obtained by sol–gel acrylamide polymerization is reported. Thermogravimetric analysis (TGA) results show between room temperature to 800 ​°C surface dehydration, decomposition of hydrochloric acid, ammonium hydroxide, decarbonization and denaturalization of the organic part. First, prepared 1:1 of Sb2O3 and Na2CO3 sol's reagents. After, each sol made was mixed with the chelating agent, EDTA (ethylenediaminetetraacetic acid) and combines with (Na+1, Sb+3) metal ions to form stable chelates, regardless the charge on the cation. To start the polymerization and accelerate the gel formation (2–3 ​s), it is added acrylamide (H2C = CHCONH2) monomer, the cross-linker, N, N'-methylene bisacrylamide (C7H10N2O2) and α,α'-azodiisobutyramidine dihydrochloride (C8H18N6·2HCl) which aid to regulate the weight of acrylamide increasing the interconnections velocity and crystal formation on a nanometric scale average 27–94 ​nm.

Development and evaluation of chitosan-g-poly(acrylic acid-co-acrylamide) hydrogel composite containing gabapentin for in vitro controlled release

In this study, a biocompatible and biodegradable hydrogel nanocomposite was synthesized through copolymerization of acrylic acid and acrylamide monomers onto chitosan in the presence of methylene bisacrylamide as a crosslinking agent and ammonium persulfate as a thermal initiator. The hydrogel was fully characterized by FTIR, SEM, DSC, and TGA techniques. The drug delivery and controlled release of gabapentin (GAB) at different pH, temperature, and time intervals were studied using the synthesized hydrogel nanocomposite. Based on the results, the maximum encapsulation and the drug loading efficiency of hydrogel composite was 64% and 71%, respectively, in which the drug was released in a sustained-release manner from the hydrogel. The release study of dual temperature and pH-responsive hydrogel composite indicated that 90% of total GAB was released from the hydrogel within the first two hours. The drug release was governed by the Higuchi kinetics model with R2= 0.9939 and followed the Fickian diffusion mechanism. The cytotoxicity of the blank hydrogel composite was evaluated on the NIH/3T3 cell line. The findings revealed that hydrogel did not affect the cells’ survival. The unique biocompatibility and thermosensitive properties of the present chitosan-based hydrogel could be a reason to use it as a promising drug carrier for the controlled and sustained release of GAB.