Gamma Radiation-induced Polymerization Research Articles

Preparation of xyloglucan-grafted poly(N-hydroxyethyl acrylamide) copolymer by free-radical polymerization for in vitro evaluation of human dermal fibroblasts

Xyloglucan is a rigid polysaccharide that belongs to the carbohydrate family. This hemicellulose compound has been widely used in biomedical research because of its pseudoplastic, mucoadhesive, mucomimetic, and biocompatibility properties. Xyloglucan is a polyose with no amino groups in its structure, which also limits its range of applications. It is still unknown whether grafting hydrophilic monomers onto xyloglucan can produce derivatives that overcome these shortcomings. This work aimed to prepare the first copolymers in which N-hydroxyethyl acrylamide is grafted onto tamarind xyloglucan by free-radical polymerization. The biocompatibility of these structures in vitro was evaluated using human dermal fibroblasts. Gamma radiation-induced graft polymerization was employed as an initiator by varying the radiation dose from 5–25 kGy. The structure of the graft copolymer, Xy-g-poly(N-hydroxyethyl acrylamide), was verified by thermal analysis, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy. The findings indicate that the degree of grafting and the cytotoxicity/viability of the xyloglucan-based copolymer were independent of dose. Notably, the grafted galactoxyloglucan exhibited efficient support for human dermal fibroblasts, showing heightened proliferative capacity and superior migration capabilities compared to the unmodified polymer. This copolymer might have the potential to be used in skin tissue engineering.

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.

Optimization of thermoresponsive hydrogels based on oligomers with lower critical solution temperature (LCST) far below/above physiological temperatures for biomedical applications

Hydrogels with oligo(ethylene glycol) (OEG), oligo(propylene glycol) (OPG), and for the first time with combined OEG/OPG pendant chains within the methacrylate (MA) network, were synthesized and the swelling behavior, thermal properties, microstructure, and genotoxicity were investigated. Prior to hydrogel fabrication, an optimized method was developed for oligo(propylene glycol) methacrylate (OPGMA), i.e., oligomer with an LCST below a temperature at which synthesis occurs, indicating that proper preparation and tuning of reaction conditions were required. PEG6MA and PPG5MA homopolymers, as well as P(EG6/PG5)MA copolymer hydrogel, were produced by gamma radiation-induced polymerization and crosslinking of OEG and OPG monomers from the monomer-solvent mixture by using different water/ethanol composition as a solvent and by exposing the reaction mixture to various radiation doses. The combination of OEG and OPG pendant chains within the same network was advantageous in that it allowed an easy tuning of the phase transition temperature. Thus, the volume phase transition (VPT) at temperatures above 70 °C observed in the case of PEG6MA, and in the case of PPG5MA at temperatures below 15 °C, could easily be tuned close to physiological temperatures for P(EG6/PG5)MA hydrogel. Finally, all obtained thermoresponsive hydrogels showed non-genotoxic and non-cytotoxic properties, which indicate promising potential for biomedical applications.

Silver nanoparticles-immobilized-radiation grafted polypropylene fabric as breathable, antibacterial wound dressing

In this work, a simplistic approach for developing an antibacterial and hydrophilic non-woven polypropylene (NWPP) fabric with excellent breathability has been presented via a two-step process. In the first step, acrylic acid was introduced onto NWPP fabric using simultaneous irradiation graft polymerization and pre-irradiation graft polymerization methods. Different grafting parameters, e.g., absorbed dose, monomer concentration, homopolymer inhibitor, reaction time, etc., were studied to optimize the grafting process. Subsequently, the acrylic acid grafted NWPP (NWPP-g-AA) fabric was immobilized with silver nanoparticles (Ag NPs), prepared from silver nitrate using trisodium citrate as reducing agent. After optimizing the grafting parameters, the NWPP-g-AA and Ag NPs-(NWPP-g-AA) samples were thoroughly characterized by grafting yield, FTIR, SEM, TEM, water contact angle, water vapor transmission rate (WVTR) and mechanical properties. The Ag NP-(NWPP-g-AA) fabric samples exhibited desired hydrophilicity, breathability and mechanical strength. Ag NP-(NWPP-g-AA) fabric samples were tested for antibacterial activity using plate count method after serial dilution, and exhibited excellent antibacterial efficacy against S.aureus (gram positive) and E.coli (gram negative) bacteria. This strategy demonstrated that a hydrophilic NWPP fabric having long-lasting antimicrobial activity was developed by gamma radiation-induced graft polymerization, which offers an ideal material for antibacterial wound dressing applications.

Effect of reaction conditions on gamma radiation-induced graft polymerization of α-methyl styrene onto polyethersulfone films: a kinetic study

Effect of reaction conditions on gamma radiation-induced graft polymerization of α-methyl styrene onto polyethersulfone films: a kinetic study

Gamma radiation-induced polymerization of polyacrylic acid-dolomite composite and applications for removal of cesium, cobalt, and zirconium from aqueous solutions

Gamma-irradiation initiated polymerization was utilized to prepare polyacrylic acid dolomite P(AA/D) nanocomposites. Different analytical techniques have been applied to investigate the structure of the new materials. XRD and TEM revealed the crystalline phase with an average particle size ranging from 2 to 4 nm. The ability of the prepared materials to remove cesium, cobalt, and zirconium ions from aqueous solutions was evaluated. The adsorption capacity of studied nanocomposites has an affinity sequence; Zr4+>Co2+≫Cs+ with values 77.8, 72.4, and 34.9 mg/g respectively. The effect of the interfering species reveals that the rate of adsorption of cesium, cobalt, and zirconium ions decreases with increasing concentrations of the interfering species. The investigation proved that the prepared nanocomposite is suitable material for the removal of the studied metals from aqueous solutions and could be considered as potential material for purification of effluent polluted with these metal ions.

Gamma radiation-induced grafting of poly(2-aminoethyl methacrylate) onto chitosan: A comprehensive study of a polyurethane scaffold intended for skin tissue engineering

A novel brush-like poly(2-aminoethyl methacrylate) (PAEMA) was grafted onto chitosan (CS) through gamma radiation-induced polymerization. The copolymer (CS-g-PAEMA) was used to prepare a sodium acetate leached poly(urethane-urea) scaffold. The above derivatives were developed, synthesized, and characterized to meet the specific characteristics of biomaterials. The results revealed that this method is an easy and successful route for grafting PAEMA onto CS. The feasibility of preparing a CS-g-PAEMA polyurethane foam was confirmed by mechanical, morphometric, spectroscopic, and cytotoxic studies. The scaffold showed high biocompatibility both in vitro and in vivo. The first experiment proved that CS-based polyurethane efficiently allows the dynamic culturing of human fibroblast cells. Additionally, an in vivo study in a murine model indicated a complete integration of the scaffold to surrounding subcutaneous tissue as supported by the histological and histochemical assessments. The aforementioned results support the use of CS-g-PAEMA poly(saccharide-urethane) as a model of in vitro-engineered skin.

Radiation-induced PEGylated Ethambutol Has Low Antimycobacterial Activity in Vitro

Tuberculosis is an airborne disease caused by Mycobacterium tuberculosis and remains one of the leading causes of death worldwide. The rise in multidrug-resistant strains has prompted the search for novel strategies to produce tuberculostatic agents. This research is aimed at developing a derivative of ethambutol by gamma radiation-induced polymerization with polyethylene glycol (PEG). The synthesis was verified by Raman spectroscopy and UV–Vis spectrometry. The results show that PEG can be chemically bonded to ethambutol by amine and alcohol groups. In in vitro biological evaluation, PEGylated and neat ethambutol showed similar cell viabilities, while the modified drug lowered bacterial growth inhibitory activity. A mechanism for the polymerization is proposed. The particle size increased for PEGylated drugs concerning the starting polyether. Despite the low antimycobacterial activity in vitro, the product seems to be a promising tool for the rapid screening of hydrolase activity.

Synthesis of chitosan-acrylic acid/multiwalled carbon nanotubes composite for theranostic 47Sc separation from neutron irradiated titanium target

A simple and efficient separation method of carrier-free 47Sc from neutron irradiated titanium target using a novel chitosan-acrylic acid/multiwalled carbon nanotubes (CS-AA/MWCNTs) composite was established. The synthesis of the CS-AA/MWCNTs composite was achieved using gamma radiation-induced template polymerization. The grafting efficiency (GE%) of AA on CS onto the surface of f-MWCNTs reached a maximum of~84% under the optimized conditions (30 wt% CS, 1.0 wt% AA, 0.15 wt% f-MWCNTs, >0.2 wt% N,N′-Methylenebisacrylamide (NMBA), and irradiation dose ~25 kGy). Different analyses (FT-IR, SEM, TGA and DTA) were examined for confirming the structural morphology and mechanical properties of the new synthesized composite. Interestingly, the CS-AA/MWCNTs composite depicted a selective adsorption of Sc(III) rather than Ti(IV) ions at pH 5 with adsorption efficiency of ~93.93%. The ionic exchange separation of no-carrier-added (NCA)47Sc(III) from irradiated TiO2 target on CS-AA/MWCNTs composite packed column efficiently eluted 47Sc(III) by 91 ± 0.8% using 1 M HCl solution. The quality control tests (radionuclidic, radiochemical, and chemical purities) for the eluted 47Sc(III) clarified its high purity and validity for cancer theranostics.

Radiation-synthesis of chitosan/poly (acrylic acid) nanogel for improving the antitumor potential of rutin in hepatocellular carcinoma.

The current study aimed to investigate the ability of chitosan/poly (acrylic acid) nanogel (CAN) to improve the bioavailability and anticancer potential of rutin. Synthesis of CAN was carried out by gamma radiation-induced polymerization of acrylic acid in an aqueous solution of chitosan. The relationship between the hydrodynamic radius of CAN and the absorbed radiation doses was also investigated. The prepared nanogels were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) techniques, and then, it was used as a nano-drug carrier for rutin. The developed formulation was evaluated for its antitumor activity against chemically induced hepatocarcinoma in rats. The following parameters were measured: aspartate and alanine aminotransferase, alkaline phosphatase, gamma glutamyltransferase, and total bilirubin as liver function test; vascular endothelial growth factor as an angiogenesis marker; α-fetoprotein as a tumor marker; and P53, caspase-3, Bax, and Bcl-2 as apoptosis markers. Histopathological examination was also confirmed. Significant enhanced anti-proliferative, anti-angiogenic, and apoptotic effects were observed for rutin-loaded CAN than free rutin, indicating that this formulation could provide a novel therapeutic approach to serve as a promising agent for treatment of hepatocellular carcinoma. Graphical abstract.

One-pot synthesis of sodium lauryl sulfate-loaded polyacrylonitrile solid-phase extractor for investigating the adsorption behavior of radioactive strontium(II) from aqueous solutions

Sodium lauryl sulfate-loaded polyacrylonitrile (SLSLPAN) was synthesized in the present investigation using an in-situ one step process through gamma radiation-induced polymerization. The structure, composition, surface area and pore size and volume of the employed adsorbent were investigated by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and nitrogen adsorption-desorption measurements. Adsorption of radioactive strontium(II) onto SLSLPAN was studied in the pH range 3–13. Batch kinetic data showed that the equilibrium was attained at 840 min and the pseudo-first-order was the best kinetic model for describing the kinetic data of the present adsorption process. The diffusion of strontium(II) into SLSLPAN was deeply studied using four diffusion models, namely, Bangham, Boyd, Weber-Morris and Mathewas-Weber models. Two-parameter (Freundlich, Langmuir and Temkin) and three-parameter (Redlich-Peterson, Toth and Generalized) isotherm models were used to analyze the adsorption equilibrium data of strontium(II) onto SLSLPAN. The maximum adsorption capacity calculated by the Generalized isotherm model is found to be 0.391 mmol strontium(II) per gram of SLSLPAN. The estimated mean free energy (E = 2.151 kJ/mol) indicated that strontium(II) radionuclides were physically adsorbed onto SLSLPAN. The value of enthalpy change (ΔHo = 35.325 kJ/mol) and those of free energy change (ΔGo = −15.278, −16.948, −18.619 and −20.288 at 303, 313, 323 and 333 K, respectively) confirmed that adsorption of strontium(II) radionuclides on SLSLPAN was endothermic and spontaneous process.

Synthesis, characterization, and in vitro evaluation of gamma radiation-induced PEGylated isoniazid

Abstract Background The search for innovative anti-tubercular agents has received increasing attention in tuberculosis chemotherapy because Mycobacterium tuberculosis infection has steadily increased over the years. This underlines the necessity for new methods of preparation for polymer-drug adducts to treat this important infectious disease. The use of poly(ethylene glycol)(PEG) is an alternative producing anti-tubercular derivatives. However, it is not yet known whether PEGylated isonicotinylhydrazide conjugates obtained by direct links with PEG are useful for therapeutic applications. Results Here, we synthesized a PEGylated isoniazid (PEG-g-INH or PEG–INH) by gamma radiation-induced polymerization, for the first time. The new prodrugs were characterized using Raman and UV/Vis spectrometry. The mechanism of PEGylated INH synthesis was proposed. The in vitro evaluation of a PEGylated isonicotinylhydrazide macromolecular prodrug was also carried out. The results indicated that PEG–INH inhibited the bacterial growth above 95% as compared with INH, which showed a lower value (80%) at a concentration of 0.25 μM. Similar trends are observed for 0.1, 1, and 5 μM. Conclusions In summary, the research suggests that it is possible to covalently attach the PEG onto INH by the proposed method and to obtain a slow-acting isoniazid derivative with little toxicity in vitro and higher anti-mycobacterial potency than the neat drug. How to cite: Gonzalez-Torres M, Guzman-Beltran S, Mata-Gomez M, et al. Synthesis, characterization, and in vitro evaluation of gamma radiation-induced PEGylated isoniazid. Electron J Biotechnol 2019; 41. https://doi.org/10.1016/j.ejbt.2019.07.005 .

Gamma radiation-induced synthesis of nanocurcumin: Characterization and cell viability test

ABSTRACTCurcumin is a bioactive agent with wide ranging therapeutic efficacy in the treatment of inflammations, wounds, microbial infections, and cancers. Despite having potent anticancer properties, its potential in cancer treatment is hampered by reduced bioavailability that mainly due to its limited solubility in water. Several studies have been performed to improve its water solubility by way of encapsulation or entrapment in nanogels or nanoparticles. These are synthesized from classical chemistry methods that involve several toxic chemicals those are difficult to purify. This study explores a novel production method to prepare nanosized curcumin (nanocurcumins) in view of avoiding the use of chemical crosslinkers and accelerants. Micellar aggregates were first synthesized by random copolymerization of N-isopropylacrylamide (NIPAAM), vinyl pyrollidone (VP), and polyethylene glycol diacrylate (PEGDA) using gamma radiation-induced polymerization. The micellar aggregates were then used to entrap curcumin in water to form nanocurcumins—making it readily soluble in water. An MTT assay test shows that lowest cell viability for MCF-7 and HEP-G2 cells was observed at 1,000 and 5,000 µM nanocurcumin concentration, respectively, while free curcumin had higher cell viability in almost all concentrations. The tests revealed that a comparable final product could be obtained using the gamma radiation-induced polymerization method.

Design of Isoniazid Smart Nanogel by Gamma Radiation-Induced Template Polymerization for Biomedical Application.

Preparation of Isoniazid (INH) loaded nanogel particles using gamma radiation as safe, simple, cheap and reproducible technique for promoting mycobacterial killing in a lower-dose system aiming in developing of drug resistance. Polymeric pH-sensitive nanogels were prepared by gamma radiation-induced polymerization of Acrylic acid (AAc) or Itaconic acid (IA), in aqueous solution of polyvinylpyrrolidone (PVP), as template polymer. The prepared nanogels were utilized for encapsulation of INH. 31X22 factorial design was employed for optimization and exploring the effect of radiation dose (X1) (30-50kGy), ratio of PVP: acid (X2) (50:50-30:70) and type of acid (X3) on the prepared nanogel characterization RESULTS: The optimized levels of X1, X2 and X3 were (50 KGy, 30:70 and Itaconic acid, respectively), with a desirability of 0.959. In-vitro INH release rate from the prepared nanogels decreased with increasing gamma radiation doses, with the predominance of the diffusion mechanism for drug release pattern. In addition, it was perceived that the minimum inhibitory concentration (MIC) of INH loaded PVP/PIA nanogels on Mycobacteria Tuberculosis was 8 folds lower than that of INH solution. The prospective of PVP-K90/PIA was recommended as a smart candidate for delivery of INH with promising achievements against tuberculosis than free drug. Graphical abstract Mechanism of formation and loading of Isoniazid PVP/PIA nanogel.

Radiation grafting of glycidyl methacrylate and divinylbenzene onto polyethylene terephthalate fabrics for improving anti-dripping performance

A new kind of anti-dripping polyethylene terephthalate (PET) fabric was successfully prepared by simultaneous gamma radiation-induced grafting polymerization of glycidyl methacrylate (GMA) and divinylbenzene (DVB) onto the surface of PET fabrics. The grafting yield (GY) and anti-dripping effect were optimized by changing the total absorbed dose, dose rate, concentration and the feed ratio of GMA and DVB. The grafting yield increased with the increase of absorbed dose and GMA monomer concentration, and decreased with the dose rate. It is confirmed that PET fabrics had been modified by Fourier transform infrared spectroscopy analysis. The tensile strength and elongation at break of modified PET fabrics were improved compared with original PET fabrics. The limiting oxygen index (LOI) of modified PET fabrics with the GY of 23–25% was 21.5, which was similar to that of unmodified PET fabrics. However, the anti-dripping performance of PET fabrics was improved remarkably after radiation modification due to the crosslinking of the sidechains grafted on the PET surface. This anti-dripping fabric may be promising for fire protective clothing.

Membranes of chitosan grafted onto poly(3-hydroxybutyrate): new insights into their applicability as scaffolds

Chitosan was grafted onto poly(3-hydroxybutyrate) (P(3HB)) as in our earlier work by using gamma radiation-induced polymerization reaction. We now provide structural and surface characteristics of the graft copolymer in view of potential applications. The modified P(3HB) was characterized by 1H/solid-state 13C CP-MAS nuclear magnetic resonance, Fourier transform infrared spectroscopy, thermogravimetric analysis, atomic force microscopy, contact angles and scratch resistance determination. Copolymer surfaces resemble those of neat P(3HB) and are unsuitable for membranes. However, a novel composite based on grafting copolymer and polyurethane was developed. It displays good properties for the preparation of 3D-scaffolds with potential uses in tissue engineering.

Modification of microcrystalline cellulose by gamma radiation-induced grafting

Abstract Modified microcrystalline cellulose (MCC) was prepared through gamma radiation-induced graft polymerization of glycidyl methacrylate (GMA). Simultaneous grafting was employed wherein MCC with GMA in methanol was irradiated with gamma radiation in nitrogen atmosphere. The effects of different experimental factors such as monomer concentration, type of solvent and absorbed dose on the degree of grafting, Dg, were studied. The amount of grafted GMA, expressed as Dg, was determined gravimetrically. Information from grafted samples subjected to Fourier transformed infrared spectroscopy (FTIR) in attenuated total reflectance (ATR) mode showed peaks corresponding to GMA which indicates successful grafting. The X-ray diffraction (XRD) analysis revealed that the crystalline region of MCC was not adversely affected after grafting with GMA. The thermogravimetric analysis (TGA) data showed that the decomposition of grafted MCC occurred at higher temperature compared to the base MCC polymer.

Tribological and Mechanical Properties of Poly[(R)-3-hydroxybutyric acid] Grafted with Vinyl Compounds: Insight into Possible Application

Biodegradable graft copolymers were prepared by gamma radiation-induced graft polymerization of two vinyl monomers, vinyl acetate and vinyl alcohol, onto poly[(R)-3-hydroxybutyric acid]. Success of the grafting reaction was verified by Fourier-transform infrared and nuclear magnetic resonance spectroscopy. Thermal remolding was used to create membranes from the copolymers. We determined tribological and mechanical properties of the membranes obtained. The lowest elongation at break in tensile testing is seen for P(3HB) and the highest for P(3HB-g-VA). Up to 5 N or so, the highest scratch resistance is exhibited by P(3HB-g-VA). Piezoelectric behavior is seen for P(3HB-g-VA) while P(3HB-g-VAc) and plain P(3HB) showed no electric response. Explanation of the piezoelectric behavior in terms of molecular structures is provided.

Adsorption behavior of samarium(III) from aqueous solutions onto PAN@SDS core-shell polymeric adsorbent

Abstract Adsorption behavior of samarium(III) radionuclides from aqueous solutions onto a novel polyacrylonitrile coated with sodium dodecyl sulfate (PAN@SDS), prepared by gamma radiation-induced polymerization, was studied in this work. The developed polymeric adsorbent was characterized by FT-IR, X-ray diffraction and N2 adsorption-desorption. The influence of some experimental parameters such as pH, initial samarium(III) concentration, SDS concentration, temperature, ionic strength and contact time on the adsorption efficiency of samarium(III) was evaluated. Results showed that adsorption efficiency of about 97% was attained for samarium(III) in the pH range 3.8–7.5. The kinetic study showed that samarium(III) was efficiently removed within 10 min and equilibrium was attained at around 30 min. Six isotherm models; Freundlich, Langmuir, Generalized, Redlich–Peterson, Toth and Sips, were used to fit the adsorption equilibrium data, and the best-fit three-parameter isotherms suggest that adsorption capacity of PAN@SDS for samarium(III) to be 97.73 mg g –1, which is a markedly high value compared to most of the other adsorbents reported for other metal ions. Using the Dubinin–Kaganer–Radushkevich (DKR) model, the mean free energy E was calculated as 1.569 kJ mol-1, which suggested that adsorption of samarium(III) was dominated by physisorption. Results of the thermodynamic parameters, ΔGo, ΔSo and ΔHo, showed that adsorption of samarium(III) onto PAN@SDS was feasible, spontaneous and exothermic in nature. Of the various studied kinetic models, the experimental kinetic data were best fitted to the modified multiplex model, and the adsorption process was mainly controlled by particle diffusion. Desorption studies showed that 95% of samarium(III) loaded on PAN@SDS were recovered using 2 mol L –1 HCl.

Batch Studies for Sorption of Ga(III), Cu(II), Ni(II) and Zn(II) Ions onto Synthetic Polymeric Resins

Poly(acrylamide-acrylic acid-dimethyl amino ethylmethacrylate), p(AM-AA-DMAEM) and Poly(acrylamide-acrylic acid)-ethylene diamine tetracetic acid disodium, p(AM-AA)-EDTANa2 were prepared by gamma radiation-induced template polymerization technique. The prepared polymeric materials were used for the sorption of Ga(III), Cu(II), Ni(II) and Zn(II) in aqueous solution. The effect of pH, weight of resins, metal ion concentrations and contact time on the sorption of these metal ions were studied.