Effect of aligning magnetic field on the magnetic and calorimetric properties of ferrimagnetic bioactive glass ceramics for the hyperthermia treatment of cancer

Fabrication of a Double Core–Shell Particle-Based Magnetic Nanocomposite for Effective Adsorption-Controlled Release of Drugs

There has been very limited work on the control loading and release of the drugs aprepitant and sofosbuvir. These drugs need a significant material for the control of their loading and release phenomenon that can supply the drug at its target site. Magnetic nanoparticles have characteristics that enable them to be applied in biomedical fields and, more specifically, as a drug delivery system when they are incorporated with a biocompatible polymer. The coating with magnetic nanoparticles is performed to increase efficiency and reduce side effects. In this regard, attempts are made to search for suitable materials retaining biocompatibility and magnetic behavior. In the present study, silica-coated iron oxide nanoparticles were incorporated with core–shell particles made of poly(2-acrylamido-2-methylpropane sulfonic acid)@butyl methacrylate to produce a magnetic composite material (MCM-PA@B) through the free radical polymerization method. The as-prepared composite materials were characterized through Fourier-transform infrared (FTIR)spectroscopy, scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), energy-dispersive X-Ray Analysis (EDX), and thermogravimetric analysis (TGA), and were further investigated for the loading and release of the drugs aprepitant and sofosbuvir. The maximum loading capacity of 305.76 mg/g for aprepitant and 307 mg/g for sofosbuvir was obtained at pH 4. Various adsorption kinetic models and isotherms were applied on the loading of both drugs. From all of the results obtained, it was found that MCM-PA@B can retain the drug for more than 24 h and release it slowly, due to which it can be applied for the controlled loading and targeted release of the drugs.

The effect of vanadium ferrite doping on the bioactivity of mesoporous bioactive glass-ceramics

Bioactive glasses are highly reactive surface materials synthesized by melting or sol–gel techniques. In this study, mesoporous bioactive glass-ceramics doped with different amounts of vanadium and iron ((60−(x + y)) SiO₂–36CaO–4P₂O₅–xV₂O₅–yFe₂O₃, x and y between 0, 5 and, 10 mole%) were synthesized using a sol–gel method. Then, their effects on particle morphology and the biomineralization process were examined in simulated body fluid (SBF). N2 adsorption isotherm analysis proved that the samples have a mesoporous structure. In addition, the Fourier-transform infrared spectroscopy (FTIR) spectra of the samples after soaking in SBF for various periods (7, 14, and 21 days) confirmed the presence of new chemical bonds related to the apatite phase, which is in accordance with scanning electron microscopy (SEM) observations. X-ray diffraction (XRD) patterns of the samples after SBF soaking showed that lower amounts of vanadium and iron were associated with the formation of a stable and more crystalline phase of hydroxyapatite. The MTT results showed that the cell viability of mesoporous bioactive glass containing 5% V₂O₅ remains more than 90% over 7 days, which indicates the biocompatibility of the samples. To conclude, further studies on these formulations are going to be carried out in future investigations for chemohyperthermia application.

Bioactive glasses are highly reactive surface materials synthesized by melting or sol–gel techniques.

Bioactive glasses and glass-ceramics for hyperthermia treatment of cancer: state-of-art, challenges, and future perspectives

Bioactive glasses and glass-ceramics are well-proven potential biomaterials for bone-tissue engineering applications because of their compositional flexibility. Many research groups have been focused to explore the utility of bioactive glass-ceramics beyond bone engineering to hyperthermia treatment of cancer. Hyperthermia refers to raising the temperature of tumor close to 44°C at which malignant cells perish with negligible harm to normal cells. Hyperthermia can be employed by many means such as by ultrasonic waves, electromagnetic waves, infrared radiations, alternating magnetic fields, etc. Magnetic bioactive glass-ceramics are advantageous over other potential candidates for thermoseeds such as nanofluids, superparamagnetic nanoparticles because they can bond not only to the natural bone but also with soft tissues in few cases, which helps regenerating the affected part due to its bioactive nature. Strict restrictions on clinical settings ( H × f < 5 × 10 9 ) force the research activities to be more focused on material characteristics to raise the implant temperature to required ranges. Lots of efforts have been made in past years to tackle these challenges and design best-suited glass-ceramics for hyperthermia treatment. This review aims to provide essential information on the concept of hyperthermia treatment of cancer and recent developments in the field of bioactive glass-ceramics for cancer treatment. The advantages and disadvantages of magnetic glass-ceramics over other potential thermoseed materials are highlighted. In this field, the major challenges are to develop magnetic glasses, which have fast and bulk crystallization with optimized magnetic phases with lower Curie and Neel temperatures.

Porous bioactive glass micro- and nanospheres with controlled morphology: developments, properties and emerging biomedical applications

In recent years, porous bioactive glass micro/nanospheres (PBGSs) have emerged as attractive biomaterials in various biomedical applications where such engineered particles provide suitable functions, from tissue engineering to drug delivery. The design and synthesis of PBGSs with controllable particle size and pore structure are critical for such applications. PBGSs have been successfully synthesized using melt-quenching and sol-gel based methods. The morphology of PBGSs is controllable by tuning the processing parameters and precursor characteristics during the synthesis. In this comprehensive review on PBGSs, we first overview the synthesis approaches for PBGSs, including both melt-quenching and sol-gel based strategies. Sol-gel processing is the primary technology used to produce PBGSs, allowing for control over the chemical compositions and pore structure of particles. Particularly, the influence of pore-forming templates on the morphology of PBGSs is highlighted. Recent progress in the sol-gel synthesis of PBGSs with sophisticated pore structures (e.g., hollow mesoporous, dendritic fibrous mesoporous) is also covered. The challenges regarding the control of particle morphology, including the influence of metal ion precursors and pore expansion, are discussed in detail. We also highlight the recent achievements of PBGSs in a number of biomedical applications, including bone tissue regeneration, wound healing, therapeutic agent delivery, bioimaging, and cancer therapy. Finally, we conclude with our perspectives on the directions of future research based on identified challenges and potential new developments and applications of PBGSs.

Glass-ceramics for cancer treatment: So close, or yet so far?

After years of research on the ability of glass-ceramics in bone regeneration, this family of biomaterials has shown revolutionary potentials in a couple of emerging applications such as cancer treatment. Although glass-ceramics have not yet reached their actual potential in cancer therapy, the relevant research activity is significantly growing in this field. It has been projected that this idea and the advent of magnetic bioactive glass-ceramics and mesoporous bioactive glasses could result in major future developments in the field of cancer. Undoubtedly, this strategy needs further developments to better answer the critical questions essential for clinical usage. This review aims to address the existing research developments on glass-ceramics for cancer treatment, starting with the current status and moving to future advances. STATEMENT OF SIGNIFICANCE: Although glass-ceramics have not yet reached their potential in cancer therapy, research activity is significantly growing. It has been speculated that this idea and the advent of modern glass-ceramics could result in significant future advances. Undoubtedly, this strategy needs further investigations and many critical questions have to be answered before it can be successfully applied for cancer treatment. This paper reviews the current state-of-the-art, starting with current products and moving onto recent developments in this field. According to our knowledge, there is a lack of a systematic review on the importance and developments of magnetic bioactive glass-ceramics and mesoporous bioactive glasses for cancer treatment, and it is expected that this review will be of interest to those working in this area.

Synthesis and characterization of Barium-Iron containing magnetic bioactive glasses: The effect of magnetic component on structure and in vitro bioactivity

CaO-P₂O₅-SiO₂-BaO-Fe₂O₃ magnetic bioactive glasses were prepared via an optimized sol-gel method. This study is focused on investigating effects of magnetic content addition on the bioactive glass properties. To this aim, we evaluate the physical, rheological, and biocompatibility properties of synthesized magnetic bioactive glass. The morphology and composition of these glasses were studied using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). The particle size was also determined using Laser Particle Size Analyzer (LPSA). The thermal measurements were carried out using Differential Thermal Analysis (DTA). For assessing the in-vitro bioactive character of synthesized glasses, the ability for apatite formation on their surface upon immersion in simulated body fluid (SBF) was checked using SEM, EDX and pH measurements. Furthermore, the Ca, Si, Ba and Fe ions in SBF were monitored using Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). The results showed that the addition of Ba and Fe in the glass composition affect formation of apatite layer onto the glass surfaces. Morphologies of the apatite layers were also different in which the bioactivity decreased with increasing Fe concentration, but the increase of Ba concentration led to an increase in bioactivity. However all of the synthesized glasses are still highly bioactive. Finally, this research demonstrates that the synthesized magnetic bioactive glasses are nontoxic and biocompatible and they can be used as thermoseeds for cancer hyperthermia studies.

Dual-responsive polymer coated superparamagnetic nanoparticle for targeted drug delivery and hyperthermia treatment

In this work, we have prepared water-soluble superparamgnetic iron oxide nanoparticles (SPIONs) coated with a dual responsive polymer for targeted delivery of anticancer hydrophobic drug (curcumin) and hyperthermia treatment. Herein, superparamagnetic mixed spinel (MnFe2O4) was used as a core material (15-20 nm) and modified with carboxymethyl cellulose (water-soluble component), folic acid (tagging agent), and dual responsive polymer (poly-N isopropylacrylamide-co-poly glutamic acid) by microwave radiation. Lower critical solution temperature (LCST) of the thermoresponsive copolymer was observed to be around 40 °C, which is appropriate for drug delivery. The polymer-SPIONs show high drug loading capacity (89%) with efficient and fast drug release at the desired pH (5.5) and temperature (40 °C) conditions. Along with this, the SPIONs show a very fast increase in temperature (45 °C in 2 min) when interacting with an external magnetic field, which is an effective and appropriate temperature for the localized hyperthermia treatment of cancer cells. The cytocompatibility of the curcumin loaded SPIONs was studied by the methyl thiazol tetrazolium bromide (MTT) assay, and cells were imaged by fluorescence microscopy. To explore the targeting behavior of curcumin loaded SPIONs, a simple magnetic capturing system (simulating a blood vessel) was constructed and it was found that ∼99% of the nanoparticle accumulated around the magnet in 2 min by traveling a distance of 30 cm. Along with this, to explore an entirely different aspect of the responsive polymer, its antibacterial activity toward an E. coli strain was also studied. It was found that responsive polymer is not harmful for normal or cancer cells but shows a good antibacterial property.