Magnetic Nanohydrogel Research Articles

Synthesis and Evaluation of Ph and Temperature Stimuli-Responsive Magnetic Nanohydrogels for Gene Delivery

The offer of gene delivery technologies as a promising approach to treating diverse diseases has revolutionized human medicine during the last two decades. So, the application of suitable vectors, particularly polymers with substrates with unique physicochemical properties for the transfer of targeted genes to logical sites for effective treatment, plays an indispensable role for more personalized medicine and improves the safety profile in response to continuing to use new medical technologies. For this purpose, we synthesized nanocarriers with a two-block cationic hydrogel, magnetic and non-magnetic, based on N-isopropyl acrylamide (NIPAM) and quaternary alkyl ammonium halide salts of DMAEMA (DMAEMAQ) with pH and temperature responsiveness via the free radical polymerization technique. The bulk properties of these co-polymers were characterized by using Fourier transform infrared spectroscopy, 1H NMR spectroscopy, Zeta potential, lower critical solution temperature (LCST), and gel electrophoresis to show the loading of nanoparticles with the gene. In the results, magnetic P[NIPAM-DMAEMAQ] hydrogel showed controllable responsive properties determined by the nature of the cationic charge +24.7 mV incorporated, nanosize around 86.95 and 91.22 nm, and efficiency loaded with the gene more than 95%. As well, the synthesized nanohydrogel exhibited a sharp volume-phase transition in water at a LCST of ∼40 °C. So, the combination of both monomers yielded an interesting system with high transfection efficiency and compliant biocompatibility characteristics, which could effectively achieve gene loading. Also, the magnetic potential of nanohydrogel was determined as a vector to deliver genes to localized sites. Notably, the synthesized combination P[NIPAM-DMAEMAQ] nanohydrogel has been considered a transfection of the biodegradable and biocompatible magnetic nanoparticle sensitive to tunable pH and temperature responsiveness, demonstrating that it will hold a promising approach as a potential carrier to improve gene delivery therapeutic efficacy in cancer and different disease treatments.

Preparation and characterization of magnetic nanohydrogel based on chitosan for 5-fluorouracil drug delivery and kinetic study

Chemotherapy is currently used for most cancer treatments, but one of the significant problems of this treatment is that it affects the healthy tissues of the body. Therefore, designing new systems for the intelligent and controlled release of these drugs in cancer tissues is one of the major challenges in the world. Hence, today, huge costs are spent designing appropriate new drug delivery systems (DDS) with controlled drug release. In this study, chitosan-polyacrylic acid encapsulated Fe3O4 magnetic nanogelic core-shell (Fe3O4@CS-PAA) was synthesized in the presence of glutaraldehyde used for loaded anticancer 5-fluorouracil (5-FU) drug. Also, the prepared Fe3O4@CS-PAA was characterized by using FT-IR, SEM, XRD, and VSM analysis. Then, drug delivery tests were carried out in the in-vitro conditions that are the simulated physiological environment and tumor tissue conditions. The drug release tests indicated that the Fe3O4@CS-PAA upgraded the rate of 5-FU release from nanogelic core-shell under tumor tissue conditions (pH 4.5) than physiological environments (pH 7.4). In addition, various models were used to investigate the drug release mechanism. Results of modeling studies of drug release showed the mechanism of 5-FU release from Fe3O4@CS-PAA controlled by Fickian diffusion.

Fabrication of a dual stimuli-responsive magnetic nanohydrogel for delivery of anticancer drugs

A dual stimuli-responsive magnetic nanohydrogel was fabricated as a potent drug delivery system (DDS) for ‘smart’ treatment of cancer by chemo/hyperthermia approach. For this objective, Fe3O4 nanoparticles (NPs) were produced via a co-precipitation approach and then modified by 3-(trimethoxysilyl) propylmethacrylate (MPS) moiety. The modified NPs were copolymerized with N,N′-(dimethylamino)ethyl methacrylate (DMAEMA), and maleic anhydride (MA) monomers by a free radical polymerization approach to afford a Fe3O4@P(DMAEMA-co-MA) core-shell NPs. Afterward, the NPs were shell crosslinked by the reaction of anhydride unites with neutralized cystamine (Cys). The fabricated pH- and reduction-responsive magnetic nanohydrogel was physically loaded with methotrexate (MTX), as an anticancer drug, and its drug loading efficiency (LE) was calculated as 64 ± 2.7%. The developed nanohydrogel/MTX exhibited proper stimuli-triggered drug release behavior that qualified it as an efficient DDS according to the abnormal micro-environment of cancerous tumors. The anticancer activity investigation using chemo/hyperthermia therapy approach by MTT-assay revealed that the nanohydrogel/MTX might show better clinical outcomes than those of the free MTX.

A biological magnetic nano-hydrogel based on basil seed mucilage: study of swelling ratio and drug delivery

Basil seed with mucilage shell contains carbohydrates (BSG) which can be extracted to produce natural hydrogel compatible with the human body. In this study, a magnetic natural hydrogel was synthesized by copolymerization between the double bonds of vinyl-modified Fe3O4/SiO2 nanoparticles, methacrylic acid (MA) as a monomer, ethylene glycol dimethacrylate (EGDMA) as a crosslinker monomer, and vinylated BSG through free radical addition polymerization for delivery of naproxen (NPX) as a model drug. The product of each reaction step was identified by FTIR technique and the morphology of nanoparticles and magnetic nano-hydrogels was investigated using the SEM technique. SEM image analysis of dry magnetic hydrogels shows the existence of a porous structure with pore size in the range of 100–300 nm. The porosity of the hydrogels used in drug delivery systems can be useful in producing a large surface area, enhancing water absorption, and facilitating drug release. The swelling behavior of nano-hydrogels, a significant feature for drug delivery systems, was investigated at different pHs in buffer solutions. Also, drug loading and delivery experiments were performed by monitoring the concentration of loaded and released NPX by absorption at 245 nm on a UV–Vis spectrophotometer. The cumulative release behavior of hydrogels was investigated and the in vitro NPX release was achieved in the range of 98% at pH 7.4 after 24 h.

A novel bioreducible and pH-responsive magnetic nanohydrogel based on β-cyclodextrin for chemo/hyperthermia therapy of cancer

A new strategy for design and development of a magnetic “smart” drug delivery system (DDS) based on β-cyclodextrin (β-CD) and poly(2-ethyl-2-oxazoline) (PEtOx) was reported. For this purpose, a β-CD-(I)7 was acetylated, and then EtOx monomer was grafted onto the acetylated β-CD-(I)7 through cationic ring-opening polymerization followed by simultaneous crosslinking with amine-end capped Fe3O4 nanoparticles (Fe3O4-NH2 NPs) and cystamine to produce a β-CD-g-(PEtOx)7/Fe3O4 as a reduction- and pH-responsive magnetic DDS. The developed magnetic nanohydrogel was loaded with doxorubicin hydrochloride (Dox), and its drug loading and encapsulation efficiencies, as well as its pH- and reduction-triggered drug release behaviors were investigated. The anticancer activity of the formulated β-CD-g-(PEtOx)7/Fe3O4-Dox was investigated against MCF7 cells. According to the results, the formulated β-CD-g-(PEtOx)7/Fe3O4-Dox can be considered as an efficient and “smart” DDS for cancer therapy and diagnosis due to its high drug loading value (∼ 74 %), slow and stimuli-triggered drug release behavior, and acceptable magnetic properties.

Pulse electromagnetic fields enhance the repair of rabbit articular cartilage defects with magnetic nano-hydrogel.

Hydrogel is an important scaffold material in regenerative medicine and cartilage tissue engineering. Hydrogel material combined with pulse electromagnetic fields (PEMFs), PEMFs has the potential to manage the repair of defective articular cartilage. Here, we developed a new type of magnetic hydrogel. The data shows that the magnetic hydrogel had good mechanical properties, and its surface had micropores and unevenness, which was conducive to cell adhesion growth. Infrared spectroscopy analysis showed that the magnetic particles were evenly distributed in the hydrogel, and the addition of constant static magnetic field yielded magnetic water. The hydrogel exhibited good superparamagnetism. The co-culture of the magnetic hydrogel and bone marrow mesenchymal stem cells (BMSCs) showed good biocompatibility. The PEMFs promoted the differentiation of the BMSCs into cartilage, and the index of cartilage differentiation increased obviously. The results of the animal experiments showed that the magnetic hydrogel and BMSCs combined with pulsed electromagnetic field had a strong repair effect. They also showed that the magnetic nano-hydrogel combined with the PEMFs induced chondrogenic differentiation of the BMSCs. The positive experimental results suggested that the combination of magnetic hydrogel and the PEMFs can be used as an effective method for repairing articular cartilage defects in rabbit model.

Synthesis of Fe3O4/PAM superparamagnetic nano-hydrogels in water-in-oil emulsion

In this study, the nano-sized water droplets (NWDs) in water-in-oil (W/O) emulsion were employed as mini-reactors, in which Fe3O4/PAM magnetic nano-hydrogels (MNHs) were obtained based on the coprecipitation and inverse emulsion polymerization. In addition, compound nonionic surfactant was used as the stabilizer of W/O emulsion. The test results showed that Fe3O4/PAM MNHs were quasi-sphere particles with a diameter of about 50–380 nm and had superparamagnetism. The percentage of PAM coating Fe3O4 was about 81%. The saturation magnetization of the Fe3O4/PAM MNHs was 21.6 emu/g (Fe3O4/AM (wt/wt) = 16.63%). The W/O emulsion containing Fe3O4/PAM MNHs (E-2) changed from fluid to solidlike in an external magnetic field. As current intensified or shear rate increased, the shear stress of E-2 increased.

Magnetic crosslinked copoly(ionic liquid) nanohydrogel supported palladium nanoparticles as efficient catalysts for the selective aerobic oxidation of alcohols

Nowadays it is still a great sustainable processes challenge to produce efficient, selective and easy magnetic recovery and recycling catalysts for oxidation of alcohols using air as the oxidant. In this work, a new magnetic nanohydrogel comprising [DABCO-allyl][Br] ionic liquid, allyl alcohol and N,N'-methylenebis(acrylamide) is used for stabilization of small and highly uniform palladium nanoparticles of 3–4 nm size MXCPILNHG@Pd. This material has been characterized by Fourier-transform infrared spectroscopy (FTIR), atomic adsorption spectroscopy (AAS), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), SEM-Map, energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectra (XPS), vibrating-sample magnetometer (VSM) and dynamic light scattering (DLS). According to optimization of cross-linking degree and ratio of DABCO-IL, MXCPILNHG-2@Pd is found as a highly selective catalyst in oxidations of primary alcohols to the corresponding aldehydes in toluene and to acids in water. Furthermore, secondary alcohols were reacted efficiently to the corresponding ketones in both toluene and water. Catalyst is magnetically recovered and recycled for several times in both toluene and water and the reused catalysts are characterized by TEM and XPS.

Three-Dimensional Rice Straw-Structured Magnetic Nanoclay-Decorated Tripolymeric Nanohydrogels as Superadsorbent of Dye Pollutants

Herein, a simple eco-friendly route was adopted to synthesize three-dimensional (3D) rice straw-structured poly(vinyl alcohol) (PVA)/ chitosan (Cs)/agar–agar (Agr), tripolymer-based magnetic nanohydrogels with incorporations of Cloisite30B and magnetite (Fe3O4) nanoparticles via sulfate-induced quick gelation approach. The 3D rice straw structures of nanohydrogels were evolved due to the rolling of exfoliated clay platelets during transformation of PVA/Cs/Agr hydrogel network, whereas the situation of exfoliation was achieved because of long time ultrasonication and strong repulsive interactions between positively charged tripolymeric chain and interstitial quaternary ammonium ions of nanoclays. Synthesized nanohydrogels were characterized with Fourier transform infrared, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, atomic force microscopy, and thermogravimetric analysis/differential thermogravimetry along with their rheological measu...

Magnetic nanohydrogel obtained by miniemulsion polymerization of poly(acrylic acid) grafted onto derivatized dextran

This study describes the synthesis of magnetic nanohydrogels by miniemulsion polymerization technique. Dextran was derivatized by the glycidyl methacrylate to anchor vinyl groups on polysaccharides backbone, allowing its use as a macromonomer for miniemulsion polymerization, as confirmed by proton nuclear magnetic resonance spectroscopy (13C NMR). Magnetite nanoparticles were synthesized by coprecipitation, followed by air oxidation to maghemite. The results of X-ray diffractometry (XRD), Raman and transmission electron microscopy (TEM) analysis showed that maghemite nanoparticles were obtained with a diameter of 5.27nm. The entrapment of iron oxide nanoparticles in a dextran nanohydrogel matrix was confirmed by thermogravimetric analysis (TGA), scanning transmission electron microscopy (STEM) and Zeta potential data. The magnetic nanohydrogels presented superparamagnetic behavior and were colloidal stable in physiological during 30days. Our findings suggest that the synthesized magnetic nanohydrogel are potential candidates for use in drug delivery systems due to its physicochemical and magnetic properties.

A novel starch-based stimuli-responsive nanosystem for theranostic applications

The aim of this study was to synthesis and characterization of a novel stimuli-responsive polymeric nanosystem for theranostic applications. For this purpose, starch was modified by itaconic anhydride to afford an itaconat-functionalized starch macromonomer (starch-IA). This macromonomer with carboxylic functional groups was subsequently adsorbed onto the surface of iron oxide nanoparticles (Fe3O4 NPs), and then copolymerized with N-isopropylacrylamide (NIPAAm) monomer via a ‘free’ radical initiated polymerization technique to produce a temperature-responsive magnetic nanohydrogel (MNHG). The chemical structures of all samples as representatives were characterized by means of Fourier transform infrared (FTIR) spectroscopy. The lower critical solution temperature (LCST), thermal responsibility, morphology, elemental composition, thermal stability, and magnetic properties of the synthesized MNHG were investigated. In addition, the methotrexate (MTX)-loading capacity (∼74%) and stimuli-responsive drug release ability of the synthesized MNHG were also evaluated. As results, we envision that the synthesized starch-g-PNIPAAm/Fe3O4 MNHG may be find theranostic applications, in part due to its smart physicochemical properties.

5‐Fluorouracil encapsulated magnetic nanohydrogels for drug‐delivery applications

ABSTRACTFor the first time, green‐tea (GT)‐based magnetic nanohydrogels were developed for drug‐delivery purposes. The hydrogel matrices were fabricated via the in situ polymerization of acrylamide with GT molecules. Magnetic nanoparticles were synthesized by the reduction of the 1:2 molar ratio mixture of ferrous sulfate heptahydrate and ferric chloride hexahydrate with an ammonia solution. A chemotherapeutic drug, 5‐fluorouracil, was chosen as a model drug, and its releasing profiles in the presence and absence of the external magnetic field were evaluated at a pH of 7.4. We observed that in the presence of the applied magnetic field, these magnetic nanohydrogels released 2.86% more drug than in the absence of a magnetic field. The magnetic nanohydrogels were characterized by X‐ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, vibrating sample magnetometry, and transmission electron microscopy. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43921.

Preparation of N-Isopropylacrylamide/Itaconic Acid Magnetic Nanohydrogels by Modified Starch as a Crosslinker for Anticancer Drug Carriers

A novel approach is presented for the synthesis of thermoresponsive and pH-sensitive magnetic nanohydrogels by using the biodegradable starch-maleate as a crosslinker and magnetic nanoparticles stabilizer. Chemically modified starch-maleate produces highly stable Fe3O4 magnetic nanopaticles (MNPs) aqueous dispersion. Then, N-isopropylacrylamide (NIPAAm) and itaconic acid (IA) are successfully polymerized from the vinyl double bonds of the starch-maleate-MNPs to prepare the thermo- and pH-responsive magnetic nanohydrogels. The obtained PNIPAAm-g-(starch-MNPs) and (PNIPAAm-co-IA)-g-(starch-MNPs) nanohydrogels are characterized by transmission electron microscopy, dynamic light scattering, Fourier transform infrared spectrometer, X-ray diffraction, differential scanning calorimetry, thermal gravimetric analysis, and vibrating sample magnetometer. Also, pH- and temperature-responsive behaviors of the synthesized magnetic nanohydrogels are investigated and, finally, the cytotoxicity and drug loading are examined with mitoxantrone (MTX) as an anticancer drug model. The results confirm the low toxicity and enhanced anticancer effect of MTX-loaded magnetic nanohydrogels.

Dual pH and temperature stimuli-responsive magnetic nanohydrogels for thermo-chemotherapy.

Dual stimuli pH and temperature-responsive nanohydrogels based on poly(N-isopropylacrylamide)-chitosan have been synthesized. Fe3O4 magnetic nanoparticles (NPs) (-12 nm) have been incorporated into hydrogels to achieve temperature optimized magnetic nanohydrogel (MNHG) for magnetic hyperthermia with lower critical solution temperature, LCST > 42 degrees C. The composite was further investigated for its potential application in drug delivery and in vitro cancer cell cytotoxicity. Water-bath assisted drug release studies were carried out using anti-cancer drug doxorubicin (DOX) in acetate buffer medium (pH - 4.6) to mimic tumor cell environment which is slightly acidic in nature. The pH and temperature responsiveness of the system was demonstrated by DOX release under different conditions. The released amount of DOX was found to be nearly 4 microg/mg above hyperthermia temperature (-42 degrees C) as opposed to only 1.9 microg/mg of MNHG at physiological temperature (37 degrees C) under acidic environment (pH - 4.6). Further, AC magnetic field (AMF) induced heating of NPs entrapped inside hydrogels showed appreciable reduction of cell population in human breast (MCF-7) and cervical carcinoma (HeLa) cell lines for given duration of field exposures. Quantitatively, death percentages of HeLa cells were nearly 35 and 45% while for MCF-7, these were 20 and 70% when exposed to AMF for 10 and 30 min, respectively. Further the cell killing efficacy of MNHG loaded with DOX was assessed under AMF using HeLa cell lines. The AMF induced heat triggered DOX release from the MNHG which enhances the cell death up to 85% due to combined effect of thermo-chemotherapeutics. The present system with both pH and temperature responsivity serves as a promising candidate for a combination therapy.

Biocompatibility, biodistribution and efficacy of magnetic nanohydrogels in inhibiting growth of tumors in experimental mice models.

We report in vivo evaluation of a thermo-responsive poly(N-isopropylacrylamide)-chitosan based magnetic nanohydrogel (MNHG) incorporated with Fe3O4 nanoparticles (NPs) in mice models with expandible scope for use in localized delivery of chemotherapeutics. Biocompatibility and biodistribution of the MNHG are studied in normal Swiss mice while efficacy in tumor growth inhibition is studied in a subcutaneous fibrosarcoma tumor. The ex vivo time-dependent pattern of accumulated MNHG into vital organs; lung, liver, spleen, kidney and brain collected at 1 h, 48 h, 7 d and 14 d post intravenous administration are investigated using both a vibrating sample magnetometer (VSM) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) method. The doses of MNHG (dose I ∼ 650 and dose II ∼ 325 μg g-1 body wt) used in the study are determined based on induced thermal activation of MNHG under an AC magnetic field (AMF). Fibrosarcoma tumor bearing mice are subjected to hyperthermia with a field of 325 Oe and 265 kHz for 30 min following intratumoral administration of dose I. Tumor size measured at an interval of 72 h for a period of 2 weeks reveals that the NPs mediated therapy decelerated the growth of the transplanted tumor by about three-fold (size, 1545 ± 720 mm3) as compared to the exponential growth of the tumor (size, 4510 ± 735 mm3) in control mice. These results suggest the feasibility of using poly(NIPAAm)-chitosan hydrogels loaded with NPs for combined thermo-chemotherapy where the efficacy may further be improved by temperature dependent release of the drugs from the magneto hydrogels.

In vitro biocompatibility of magnetic thermo-responsive nanohydrogel particles of poly(N-isopropylacrylamide-co-acrylic acid) with Fe3O4 cores: Effect of particle size and chemical composition

Biocompatibility is a critical factor in the design and development of candidate materials for biomedical use. This paper reports on the in vitro biocompatibility of magnetic stimuli-sensitive nanohydrogel particles composed of magnetite cores in poly(N-isopropylacrylamide-co-acrylic acid) shells referred to Fe3O4/P(NIPAAm-co-AAc). The AAc concentration and polymerization time were varied to fabricate magnetic nanoparticles with various AAc levels (1.80–2.37%) and particle sizes (74–213nm). The P(NIPAAm-co-AAc) shell exhibited thermo-sensitive properties and the Fe3O4 core constituted 2.25–4.10% of the particles by weight. After a 2-day incubation of L929 cells with extract media that had been conditioned with various test samples, the cellular responses were monitored in terms of cell viability and growth. The Live/Dead assays showed that high levels of cellular viability (97.3–98.1%) were observed in all groups, indicating that none of the nanoparticles were cytotoxic. However, the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymetho-xyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assays demonstrated that the activity of mitochondrial dehydrogenase varied significantly in cultures exposed to different magnetic nanohydrogel particles. The murine fibroblasts exposed to the NIP-(AAc5.1-Fe)-2 sample, which contained the highest AAc content and largest particle sizes, were the least metabolically active. In contrast, the activity levels in the cultures treated with the low AAc content and small size particles (NIP-(AAc2.6-Fe)-1) were not significantly different from those in the control group. Our findings suggest that smaller magnetic stimuli-sensitive nanohydrogel particles with a lower AAc content may have little inhibitory impact on cell proliferation. Overall, the in vitro biocompatibilities of the nanoparticles depend on the chemical composition and size of the Fe3O4/P(NIPAAm-co-AAc) particles.

A comparative study on thermoresponsive magnetic nanohydrogels: role of surface-engineered magnetic nanoparticles

A comparative study of thermoresponsive poly(N-isopropylacrylamide)(PNIPAAm)-chitosan (CS)-based magnetic nanohydrogels (MNHGs) encapsulating functionalized Fe3O4 nanoparticles (NPs) in terms of the parameters governing their suitability for real hyperthermia is reported. Iron oxide NPs functionalized with (a) citric acid (CA-Fe3O4), (b) ethylenediamine (Amine-Fe3O4) and (c) dimercaptosuccininc (DMSA-Fe3O4) have been synthesized and their encapsulation into MNHGs was obtained through physical encapsulation method. The structural characterizations of synthesized materials include X-ray diffraction, FT-IR, TGA, ICP-AES and X-ray photoelectron spectroscopy (XPS). Encapsulation of the functionalized NPs into MNHGs were observed in TEM micrographs, while SEM and AFM micrographs confirmed their spherical morphology (~250–300 nm). Lower critical solution temperature (LCST) variation was measured by UV–visible spectrophotometer and differential scanning calorimetry (DSC). MNHGs exhibited sufficient magnetization and heating ability for hyperthermia. Typically, hydrogels containing CA-Fe3O4 (50 mg/ml) raised the temperature of the medium to 43 °C, a suitable dose for in vivo application in tumor-bearing mice.

Thermal behavior of magnetically modalized poly( N-isopropylacrylamide)-chitosan based nanohydrogel

Poly(NIPAAm)-CS based nanohydrogels (NHGs) and iron oxide (Fe 3O 4) magnetic nanoparticles encapsulated magnetic nanohydrogels (MNHGs) were synthesized by free radical polymerization of N-isopropylacrylamide (NIPAAm) at 60 °C in presence of chitosan (CS) in different feed ratios. The polymerization of NIPAAm and the presence of CS as well as Fe 3O 4 in hydrogels were confirmed from Fourier transform infrared (FTIR) spectra and X-ray diffraction (XRD), respectively. 13C solid state nuclear magnetic resonance (NMR) spectra clearly revealed the grafting of CS into poly(NIPAAm). The scanning electron microscopy (SEM) and atomic force microscopy (AFM) images showed the formation of spherical shaped NHGs of different sizes ranging from 50 nm to 200 nm depending upon the feed ratios of CS and NIPAAm, which was further supported by mean hydrodynamic diameter measured by dynamic light scattering (DLS). It has been observed that CS not only served as a cross linker during polymerization but also plays a critical role in controlling the growth of NHG and enhancement in lower critical solution temperature (LCST). The encapsulation of Fe 3O 4 nanoparticles (10–12 nm) into NHGs (∼200 nm) was confirmed by transmission electron microscopy (TEM) and further corroborated with magnetic force microscopy (MFM) image. The LCST of poly(NIPAAm) was found to increase with increasing weight ratio of CS to NIPAAm. Furthermore, the encapsulation of iron oxide nanoparticles into hydrogels also caused an increment in LCST. Specifically, temperature optimized NHG and MNHG were fabricated having LCST close to 42 °C (hyperthermia temperature). The MNHG shows optimal magnetization, good specific absorption rate (under external AC magnetic field) and excellent cytocompatibility with L929 cell lines, which may find potential applications in hyperthermia treatment of cancer and targeted drug delivery.