Hyperthermic Response Research Articles

Simultaneous hyperthermia and doxorubicin delivery from polymer-coated magnetite nanoparticles

In this work, the hyperthermia response, (i.e., heating induced by an externally applied alternating magnetic field) and the simultaneous release of an anti-cancer drug (doxorubicin) by polymer-coated magnetite nanoparticles have been investigated. After describing the setup for hyperthermia measurements in suspensions of magnetic nanoparticles, the hyperthermia (represented by the rate of suspension heating and, ultimately, by the specific absorption rate or SAR) of magnetite nanoparticles (both bare and polymer-coated as drug nanocarriers) is discussed. The effect of the applied ac magnetic field on doxorubicin release is also studied, and it is concluded that the field does not interfere with the release process, demonstrating the double functionality of the investigated particles.

Magnetic hyperthermia with magnetite nanoparticles: electrostatic and polymeric stabilization

In this work, magnetic hyperthermia, i.e., heating induced by an alternating magnetic field acting on a magnetic suspension, is considered in three main aspects. The first one regards the implementation of a simple device for producing AC magnetic fields. The second contribution concerns the comparison of the hyperthermia response (measured by the specific absorption rate (SAR)) of magnetite nanoparticles of two different sizes and of raw particles vs. polyelectrolyte-coated ones. An improvement is observed of the SAR values when the pH is fixed away from the isoelectric point or when the ionic strength is kept at low values. The addition of a polymer enhances significantly the stability of the suspensions and so does with the SAR values. Finally, we describe the implementation of a sort of magnetic hyperthermia applicator, avoiding the necessity of placing the magnetic sample inside the coil and making it of more practical use.

Acute hyperthermic responses of heat shock protein and estrogen receptor mRNAs in rainbow trout hepatocytes

Heat shock proteins (HSPs) are induced upon elevated temperature in fishes. HSPs also function as molecular chaperones for cellular proteins, including steroid hormone receptors. Estrogen receptors (ERs) are critical for the hormone signaling necessary during the liver production of the yolk precursor protein vitellogenin in oviparous vertebrates. Considering the possible regulatory role of HSPs on the ER signaling pathway, the present study characterized the mRNA expression of all known isoforms of HSP70 (hsp70a, hsp70b), HSP90 (hsp90a1a, hsp90a1b, hsp90a2a, hsp90a2b, hsp90b1, hsp90b2), and ERs (erα1, erα2, erβ1, erβ2) in Rainbow Trout hepatocytes following an acute heat shock (1h at 25°C) compared to a control treatment (12°C). The results showed that the mRNA levels of hsp70a, hsp70b, hsp90a1b, hsp90a2a, and hsp90b2 were significantly increased after heat shock, while erα1 mRNA levels were significantly reduced by this treatment. hsp90a1a, hsp90a2b, hsp90b1, erα2, erβ1 and erβ2 were unaffected by this acute hyperthermic treatment. Comparatively, the responses of the two hsp70 isoforms were much greater than the hsp90 isoforms. Acute heat shock treatment of hepatocytes followed by a 24h exposure to 17β-estradiol (E2) exposure also resulted in decreased expression of erα1 mRNA, but not vitellogenin (vtg) mRNA. This study showed that some hsp70 and hsp90 isoforms display a robust response to an acute hyperthermic treatment in Rainbow Trout hepatocytes. Among the transcripts measured here, the erα1 isoform uniquely showed significantly decreased mRNA levels upon acute heat treatment.

Optimizing magnetic anisotropy of La1−xSrxMnO3 nanoparticles for hyperthermia applications

Maximizing the magnetothermal response of magnetic nanoparticles (MNP's) for hyperthermia applications is a complex problem, because it depends sensitively upon interrelated magnetic and structural parameters. The task is somewhat simpler for systems with fixed composition, e.g. Fe3O4 or CoFe2O4, in which the particle size is the only means of modifying the magnetic anisotropy, and hence the magnetothermal response. In the La1−xSrxMnO3 system however, the magnetic interactions as well as the particle size both change with the Sr concentration x, which makes it a much more complex system for which to optimize the hyperthermia response. We have investigated the effect of magnetic anisotropy on the magnetothermal response of La1−xSrxMnO3 nanoparticles as a function of the particle size as well as the Sr concentration x where 0.20≤x≤0.45. The optimum particle size range is 25–30nm for all concentrations, where the specific absorption rate (SAR) has a maximum. The linear response theory (LRT) has been applied to this system and good agreement has been found between the experimental and theoretically determined values of the SAR for samples lying in the single domain regime and having large enough anisotropy energies. The agreement is much better for the intermediate concentrations of 0.27 and 0.33, because of their large anisotropy as compared to other concentrations. It is concluded that the LRT can be successfully used to predict the SAR of these nanoparticles, provided they possess large enough effective anisotropies. Values of the ILP have been obtained for these samples and found to be comparable to those of magnetite and some commercial ferrofluids.

Effects of turmeric curcuminoids and metformin against central sensitivity to pain in mice

The reported experimental study was conducted to compare the effects of repeated daily oral doses of curcuminoids (CLE) with metformin as potential antidepressants and analgesics. Effects of a single and ten daily oral doses of CLE (5, 20, 80 mg/kg/day) and of 50 mg/kg/day metformin (MET) were compared in mice hot plate test (HPT) for analgesics. On the 11th treatment day, all animals were subjected to foot shock stress triggered hyperthermia test, and on the 12th treatment day to tail suspension test (TST) for antidepressants. Immediately thereafter, their blood levels of glucose, insulin and cortisol were quantified. Dose dependent analgesic activity of CLE was observed in HPT, whereas the metformin dose tested suppressed only pain hypersensitivity in the test. But statistically significant effects of both of them were observed in TST, and both of them also afforded protections against body weight loss and slight elevation in core temperatures induced by daily handling and repeated testing. CLE or metformin had no significant effects in foot shock stress triggered transient hyperthermic responses or on blood glucose, insulin and cortisol levels. Reported results reveal that curcuminoids as well as metformin are stress response modifiers with antidepressants like activities, but only low dose curcuminoids possess centrally acting analgesics like activities. They suggest that the bio-assay system used in this study is well suited for identifying curcuminoids like plant metabolites with analgesic and anti-stress activities, and that low dose curcuminoids are more effective as analgesics than low dose metformin.

Biodegradable Radiofrequency Responsive Nanoparticles for Augmented Thermal Ablation Combined with Triggered Drug Release in Liver Tumors.

Radiofrequency ablation (RFA) and doxorubicin (Dox) chemotherapy are separately approved for liver cancer therapy; however, both have limited success in the clinic due to suboptimal/nonuniform heating and systemic side effects, respectively. Here, we report a biodegradable nanoparticle (NP) system showing excellent RF hyperthermic response together with the ability to locally deliver Dox in the liver under RF trigger and control. The nanosystem was prepared by doping a clinically permissible dose (∼4.3 wt %, 0.03 ppm) of stannous ions in alginate nanoparticles (∼100 nm) coloaded with Dox at ∼13.4 wt % concentration and surface conjugated with galactose for targeting asialo-glycoprotein receptors in liver tumors. Targeted NP-uptake and increased cytotoxicity when combined with RF exposure was demonstrated in HEPG2 liver cancer cells. Following in vitro (chicken liver phantom) demonstration of locally augmented RF thermal response, in vivo scintigraphic imaging of 99Tc-labeled NPs was performed to optimize liver localization in Sprague-Dawley (SD) rats. RF ablation was performed in vivo using a cooled-tip probe, and uniformly enhanced (∼44%) thermal ablation was demonstrated with magnetic resonance imaging along with RF-controlled Dox release. In orthotopic rat liver tumor models, real-time infrared imaging revealed significantly higher (∼20 °C) RF thermal response at the tumor site, resulting in uniform augmented ablation (∼80%) even at a low RF power exposure of 15 W for just 1 min duration. Being a clinically acceptable, biodegradable material, alginate nanoparticles hold strong translational potential for augmented RF hyperthermia combined with triggered drug release.

Impact of Functional Group Modifications on Designer Phenethylamine Induced Hyperthermia.

The popularity of designer phenethylamines such as synthetic cathinones ("bath salts") has led to increased reports of life-threatening hyperthermia. The diversity of chemical modifications has resulted in the toxicological profile of most synthetic cathinones being mostly uncharacterized. Here, we investigated the thermogenic effects of six recently identified designer phenethylamines (4-methylmethamphetamine, methylone, mephedrone, butylone, pentylone, and MDPV) and compared these effects to the established thermogenic agent 3,4-methylenedioxymethamphetamine (MDMA). Specifically, we determined the impact of a β-ketone, α-alkyl, or pyrrolidine functional group on core-body temperature changes. Sprague-Dawley rats (n = 5-6) were administered a dose (30 mg/kg, sc) of a designer phenethylamine or MDMA, and core body temperature measurements were recorded at 30 min intervals for 150 min post treatment. MDMA elicited the greatest maximum temperature change (ΔTmax), and this effect was significantly greater than that of its β-ketone analogue, methylone. Temperature-area under the curves (TAUCs) and ΔTmax were also significantly different between 4-methylmethamphetamine (4-MMA) and its β-ketone analogue mephedrone. Lengthening the α-alkyl chain of methylone to produce butylone and pentylone significantly attenuated the thermogenic response on both TAUCs and ΔTmax compared to those of methylone; however, butylone and pentylone were not different from each other. Pyrrolidine substitution on the N-terminus of pentylone produces 3,4-methylenedioxypyrovalerone (MDPV), which did not significantly alter core body temperature. Thermogenic comparisons of MDMA vs methylone and 4-MMA vs mephedrone indicate that oxidation at the benzylic position significantly attenuates the hyperthermic response. Furthermore, either extending the α-alkyl chain to ethyl and propyl (butylone and pentylone, respectively) or extending the α-alkyl chain and adding a pyrrolidine on the N-terminus (MDPV) significantly blunted the thermogenic effects of methylone. Overall, the present study provides the first structure-activity relationship in vivo toxicological analysis of designer phenethylamines.

Sustained housing-type social buffering following social housing in male rats

In social animals, recovery from the adverse effects of distressing stimuli is promoted by subsequent cohousing with a conspecific animal(s). This phenomenon has been termed housing-type social buffering. We previously found that social housing induced housing-type social buffering in fear-conditioned male rats. This buffering took the form of attenuated conditioned hyperthermia in response to an auditory conditioned stimulus (CS). Here, we assessed whether this social buffering is sustained even if the subject is housed alone after a period of social housing. When fear-conditioned subjects were housed alone during a 48-h period between conditioning and re-exposure to the auditory CS, they exhibited conditioned hyperthermia in response to the CS. However, conditioned hyperthermia was not observed when the 12-h period of social housing began 24 and 36h after conditioning during the 48-h period. This was not the case when the 12-h period of social housing began 0 and 12h after the conditioning. These results suggest that housing-type social buffering is sustained for 12h after the 12-h period of social housing. We next considered whether increasing the duration of social housing would extend the period of social buffering. We observed social buffering of conditioned hyperthermia 24 and 48, but not 96h after a 24-h period of social housing. These results suggest that social buffering was extended when the duration of social housing was increased. Taken together, our findings indicate that housing-type social buffering is sustained after a period of social housing.

Stimuli-responsive poly(N-isopropyl acrylamide)-co-tyrosine@gadolinium: Iron oxide nanoparticle-based nanotheranostic for cancer diagnosis and treatment

In this paper, we have prepared a stimuli-responsive polymer modified gadolinium doped iron oxide nanoparticle (poly@Gd-MNPs) as cancer theranostic agent. The responsive polymer is composed of the poly(N-isopropyl acrylamide)-co-tyrosine unit, which shows excellent loading for the anti-cancer drug (methotrexate) and stimuli dependent release (change in pH and temperature). The in vitro experiment revealed that the poly@Gd-MNPs exhibited T1-weighted MRI capability (r1=11.314mM−1s−1) with good in-vitro hyperthermia response. The prepared poly@Gd-MNPs has generated quick heating (45°C in 2min) upon exposure to an alternating magnetic field and able to travel a distance of 35cm in 1min in the presence of an external magnet. The poly@Gd-MNPs shows 86% of drug loading capacity with 70% drug release in first 2h. The cytotoxic assay (MTT) demonstrated that the nanoparticle did not affect the viability of normal human fibroblast and efficiently kill the MCF7 cancer cells in the presence of an external magnetic field. To explore the uptake of poly@Gd-MNPs in the cells, bright field cell imaging study was also performed. This study provides a valuable approach for the design of highly sensitive polymer modified gadolinium doped iron oxide-based T1 contrast agents for cancer theranostics.

Optimum nanoscale design in ferrite based nanoparticles for magnetic particle hyperthermia

The study demonstrates the multiplex enhancement of the magnetic hyperthermia response by nanoscale design and magnetism tuning without sparing the biocompatibility of iron-oxide.

Commentary: Yawning, acute stressors, and arousal reduction in Nazca booby adults and nestlings.

Commentary: Yawning, acute stressors, and arousal reduction in Nazca booby adults and nestlings.

Hyperthermic intra-peritoneal chemotherapy and anticancer immune response

Peritoneal carcinomatosis (PC) is a metastatic disease of primary tumors localized in the abdomen. Although this disease is considered a terminal condition, recent treatments combining surgery with heated intra-peritoneal chemotherapy (HIPEC) significantly increase patient survival. We have determined that the protective effect of HIPEC is partially linked to the induction of an efficient anticancer immune response.

The Profile of Exercise‐induced Neuronal Activation in Autonomic Control Nuclei Changes According to Thermoregulatory Phase

The purpose of this study was to examine whether the neuronal recruitment induced by exercise in autonomic nuclei is dependent of thermoregulatory phase and/or physical performance. Rats that were subjected to submaximal running exercise stopped in 3 different times: REST (control group), NADIR (the minimum heat dissipation phase), 20MIN (the stabilization phase of both body temperature ‐ Tb ‐ and tail skin temperature ‐ Tsk), and FATIGUE (Tb and Tsk reach their highest values​).The brains were removed and processed for determination of c‐Fos expression in the medial, median, and ventromedial preoptic areas (mPOA, mnPOA, and vmPOA, respectively), and paraventricular and supraoptic nucleus of hypothalamus (PVN and SON, respectively). Physical exercise induced an increase of c‐Fos expression in all brain areas. The c‐Fos expression in the vmPOA was similar for all exercising groups, while for mPOA, mnPOA, and PVN, it was gradually increased as the exercise and hyperthermic response are prolonged. Only after 20 min of exercise an increase in SON c‐Fos expression was verified. The neuronal recruitment within the mPOA, mnPOA, PVN, and SON was directly correlated to both physical performance and heat storage. The thermoregulatory brain areas are recruited even at small Tb changes, while the SON is recruited only when Tb reaches its higher values, possibly inducing changes on fluid balance. The recruitment rate in these areas is also influenced by duration of stress stimulus, either by increasing running time, as the prolonged hyperthermic response arising of exercise. Cnpq, Capes, and Fapemig.

The Effects of Nmda Antagonists On Morphine Induced Hyperthermia in Rats

Objectives NMDA receptor antagonists, are known for their anesthetic, analgesic and anti-shivering properties. This study is aimed at evaluating the effects of ketamine and magnesium sulphate on body temperature in rats, and to determine the type of interaction between them. Methods The body temperature was measured by insertion of a thermometer probe 5 cm into the colon of unrestrained male Wistar rats (200-250 g). Results Magnesium sulphate (5 and 60 mg/kg, sc) showed influence neither on baseline, nor on morphine-evoked hyperthermic response. Subanesthetic doses of ketamine (5-30 mg/kg, ip) given alone, produced significant dose-dependent reduction in both baseline colonic temperature and morphine-induced hyperthermia. Analysis of the log dose–response curves for the effects of ketamine and ketamine-magnesium sulphate combination on the baseline body temperature revealed synergistic interaction, and about 5.3 fold reduction in dosage of ketamine when the drugs were applied in fixed ratio (1:1) combinations. In addition, fixed low dose of magnesium sulphate (5 mg/kg, sc) enhanced the temperature lowering effect of ketamine (1.25-10 mg/kg, ip) on baseline body temperature and morphine-induced hyperthermia by factors of about 2.5 and 5.3, respectively. Conclusion This study is first to demonstrate the synergistic interaction between magnesium sulphate and ketamine in lowering morhine induced hyperthermia. It is possible that the synergy between ketamine and magnesium may have clinical relevance.

Age-related alterations in the central thermoregulatory responsiveness to alpha-MSH

Alpha-melanocyte-stimulating-hormone (alpha-MSH) is a neuropeptide that induces weight loss via its anorexigenic and hypermetabolic/hyperthermic effects. Two major public health problems of the human population involving energy balance (i.e. middle-aged obesity and aging cachexia) also appear in other mammals, therefore age-related regulatory alterations may also be assumed in the background.Previous studies demonstrated characteristic age-related shifts in the anorexigenic effects of centrally applied alpha-MSH with strong effects in young adult, diminished efficacy in middle-aged and very pronounced responsiveness in old rats. The present study aimed to investigate age-related changes in the acute central thermoregulatory responsiveness to an alpha-MSH injection in rats and to compare them with those of food intake-related responsiveness. Oxygen consumption (VO2), core (Tc) and tail skin temperatures (Ts, indicating heat loss) of male Wistar rats of different age groups (from 2 to 24 months of age), were recorded in an indirect calorimeter complemented by thermocouples upon intracerebroventricular alpha-MSH administration (0, 5µg) at a slightly subthermoneutral environment (25–26°C).Acute alpha-MSH-induced rises in VO2 and Tc were most pronounced in the young adult age-group. In these rats the hyperthemic effects were somewhat diminished by an activation of heat loss. Juvenile animals showed weaker hyperthermic responses, middle-aged rats none at all. Alpha-MSH-induced hyperthermia became significant again in old rats.Acute thermoregulatory (hypermetabolic/hyperthermic) responsiveness to alpha-MSH shows a distinct age-related pattern similar to that of acute anorexigenic responsiveness.Thus, our results may also contribute to the explanation of both middle-aged obesity and aging cachexia.

Long lasting preventive effects of piperlongumine and a Piper longum extract against stress triggered pathologies in mice

Aim:To compare doxycycline (DOX) such as oral efficacies of piperlongumine (PL) and a Piper longum fruits extract (PLE) as stress resistance inducers.Materials and Methods:Efficacies of oral pretreatments with 5 mg/kg PL or PLE or of 50 mg/kg DOX for 10 consecutive days against stress resistance were compared. Mice in treated groups were subjected to a stress induced hyperthermia on the 1st, 5th, 7th, and 10thday. Treated mice were then subjected to tail suspension test on the 11thday. Alteration in body weights, core temperatures, and gastric ulcers triggered by occasional exposures to foot shocks were determined.Results:DOX like long-lasting protective effects of PL and PLE against gradual alterations in body weights, basal temperatures and transient hyperthermic responses triggered by foot shocks during the post-treatment days were observed. Altered responses of stressed mice in tail suspension test observed 1 day after the last foot-shock exposures and gastric ulcers and other pathologies quantified 1 day after the test were also suppressed in PL or PLE or DOX pretreated groups.Conclusion:PL and crude PLE are DOX like long-acting desensitizers of stress triggered co-morbidities. Reported observations add further experimental evidences justifying traditionally known medicinal uses of P. longum and other plants of the Piperaceae family, and reveal that PL is also another very long acting and orally active inducer of stress resistance. Efforts to confirm stress preventive potentials of low dose plant-derived products enriched in PL or piperine like amide alkaloids in volunteers and patients can be warranted.

Enhanced biomedical heat-triggered carriers via nanomagnetism tuning in ferrite-based nanoparticles

Biomedical nanomagnetic carriers are getting a higher impact in therapy and diagnosis schemes while their constraints and prerequisites are more and more successfully confronted. Such particles should possess a well-defined size with minimum agglomeration and they should be synthesized in a facile and reproducible high-yield way together with a controllable response to an applied static or dynamic field tailored for the specific application. Here, we attempt to enhance the heating efficiency in magnetic particle hyperthermia treatment through the proper adjustment of the core–shell morphology in ferrite particles, by controlling exchange and dipolar magnetic interactions at the nanoscale. Thus, core–shell nanoparticles with mutual coupling of magnetically hard (CoFe2O4) and soft (MnFe2O4) components are synthesized with facile synthetic controls resulting in uniform size and shell thickness as evidenced by high resolution transmission electron microscopy imaging, excellent crystallinity and size monodispersity. Such a magnetic coupling enables the fine tuning of magnetic anisotropy and magnetic interactions without sparing the good structural, chemical and colloidal stability. Consequently, the magnetic heating efficiency of CoFe2O4 and MnFe2O4 core–shell nanoparticles is distinctively different from that of their counterparts, even though all these nanocrystals were synthesized under similar conditions. For better understanding of the AC magnetic hyperthermia response and its correlation with magnetic-origin features we study the effect of the volume ratio of magnetic hard and soft phases in the bimagnetic core−shell nanocrystals. Eventually, such particles may be considered as novel heating carriers that under further biomedical functionalization may become adaptable multifunctional heat-triggered nanoplatforms.

Adaptogenic potential of andrographolide: An active principle of the king of bitters (Andrographis paniculata)

Andrographolide is a major bioactive secondary plant metabolite isolated Andrographis paniculata (Burm. F.) Wall. Ex. Nees. (穿心蓮 chuān xīn lián), a well-known traditionally used medicinal herb. The aim of the study was to pharmacologically evaluate the beneficial effect of andrographolide on stress-induced thermoregulatory and other physiological responses in mice. A stress-induced hyperthermia test was conducted in mice. The test agents were orally administered once daily for 11 consecutive days, and treatment effects on body weight changes, basal rectal temperature, and foot-shock-triggered hyperthermic responses were quantified on Day 1, Day 5, Day 7, and Day 10 of the experiments. Pentobarbital-induced hypnosis was quantified on the 11th day of treatment. Observations made during a pilot dose finding experiment revealed that, like A. paniculata extracts, pure andrographolide also possess adaptogenic properties. Observed dose-dependent efficacies of 3 mg/kg/d, 10 mg/kg/d, and 30 mg/kg/d andrographolide in the pilot experiment were reconfirmed by conducting two further analogous experiments using separate groups of either male or female mice. In these confirmatory experiments, efficacies of andrographolide were compared with that of 5 mg/kg/d oral doses of the standard anxiolytic diazepam. Significantly reduced body weights and elevated core temperatures of the three vehicle-treated control groups observed on the 5th day and subsequent observational days were completely absent even in the groups treated with the lowest andrographolide dose (3 mg/kg/d) or diazepam (5 mg/kg/d). Benzodiazepine-like potentiation of pentobarbital hypnosis was observed in andrographolide-treated animals. These observations reveal that andrographolide is functionally a diazepam-like desensitizer of biological mechanisms, and processes involved in stress trigger thermoregulatory and other physiological responses.

Stress-induced core temperature changes in pigeons (Columba livia)

Changes in body temperature are significant physiological consequences of stressful stimuli in mammals and birds. Pigeons (Columba livia) prosper in (potentially) stressful urban environments and are common subjects in neurobehavioral studies; however, the thermal responses to stress stimuli by pigeons are poorly known. Here, we describe acute changes in the telemetrically recorded celomatic (core) temperature (Tc) in pigeons given a variety of potentially stressful stimuli, including transfer to a novel cage (ExC) leading to visual isolation from conspecifics, the presence of the experimenter (ExpR), gentle handling (H), sham intracelomatic injections (SI), and the induction of the tonic immobility (TI) response. Transfer to the ExC cage provoked short-lived hyperthermia (10–20min) followed by a long-lasting and substantial decrease in Tc, which returned to baseline levels 2h after the start of the test. After a 2-hour stay in the ExC, the other potentially stressful stimuli evoked only weak, marginally significant hyperthermic (ExpR, IT) or hypothermic (SI) responses. Stimuli delivered 26h after transfer to the ExC induced definite and intense increases in Tc (ExpR, H) or hypothermic responses (SI). These Tc changes appear to be unrelated to modifications in general activity (as measured via telemetrically recorded actimetric data). Repeated testing failed to affect the hypothermic responses to the transference to the ExC, even after nine trials and at 1- or 8-day intervals, suggesting that the social (visual) isolation from conspecifics may be a strong and poorly controllable stimulus in this species. The present data indicated that stress-induced changes in Tc may be a consistent and reliable physiological parameter of stress but that they may also show stressor type-, direction- and species-specific attributes.

Tunable AC Magnetic Hyperthermia Efficiency of Ni Ferrite Nanoparticles

Nickel ferrite nanoparticles, with sizes lying within the superparamagnetic ferrimagnetic transition region, were synthesized using the solvothermal and the thermal decomposition method. Iron and nickel precursors as well as a variety of surfactants were used at adequate proportions to achieve structural and morphological, and hence magnetic tuning of the nanoparticles. X-ray diffraction and electron microscopy were used to visualize the actual particle size, morphology, and monodispersity aspects and to verify the obtained crystal structure. The magnetic hyperthermia response of nickel ferrite nanoparticles and the corresponding mechanisms of heating losses are studied in an effort to unravel the interconnections between the physical properties of magnetic nanoparticles and the tunable ac magnetic hyperthermia efficiency.