Instantaneous drug delivery of magnetic/thermally sensitive nanospheres by a high-frequency magnetic field

Drug Delivery Approaches to Improve Tendon Healing

Tendon injuries disrupt the transmission of forces from muscle to bone, leading to chronic pain, disability, and a large socioeconomic burden. Tendon injuries are prevalent; there are over 300,000 tendon repair procedures a year in the United States to address acute trauma or chronic tendinopathy. Successful restoration of function after tendon injury remains challenging clinically. Despite improvements in surgical and physical therapy techniques, the high complication rate of tendon repair procedures motivates the use of therapeutic interventions to augment healing. While many biological and tissue engineering approaches have attempted to promote scarless tendon healing, there is currently no standard clinical treatment to improve tendon healing. Moreover, the limited efficacy of systemic delivery of several promising therapeutic candidates highlights the need for tendon-specific drug delivery approaches to facilitate translation. This review article will synthesize the current state-of-the-art methods that have been used for tendon-targeted delivery through both systemic and local treatments, highlight emerging technologies used for tissue-specific drug delivery in other tissue systems, and outline future challenges and opportunities to enhance tendon healing through targeted drug delivery.

Multifunctional Iron Oxide Magnetic Nanoparticles for Biomedical Applications: A Review

Due to their good magnetic properties, excellent biocompatibility, and low price, magnetic iron oxide nanoparticles (IONPs) are the most commonly used magnetic nanomaterials and have been extensively explored in biomedical applications. Although magnetic IONPs can be used for a variety of applications in biomedicine, most practical applications require IONP-based platforms that can perform several tasks in parallel. Thus, appropriate engineering and integration of magnetic IONPs with different classes of organic and inorganic materials can produce multifunctional nanoplatforms that can perform several functions simultaneously, allowing their application in a broad spectrum of biomedical fields. This review article summarizes the fabrication of current composite nanoplatforms based on integration of magnetic IONPs with organic dyes, biomolecules (e.g., lipids, DNAs, aptamers, and antibodies), quantum dots, noble metal NPs, and stimuli-responsive polymers. We also highlight the recent technological advances achieved from such integrated multifunctional platforms and their potential use in biomedical applications, including dual-mode imaging for biomolecule detection, targeted drug delivery, photodynamic therapy, chemotherapy, and magnetic hyperthermia therapy.

Targeted pulmonary drug delivery in coronavirus disease (COVID-19) therapy: A patient-specific in silico study based on magnetic nanoparticles-coated microcarriers adhesion

Since the beginning of the COVID-19 pandemic, nearly most confirmed cases develop respiratory syndromes. Using targeted drug delivery by microcarriers is one of the most important noteworthy methods for delivering drugs to the involved bronchi. This study aims to investigate the performance of a drug delivery that applies microcarriers to each branch of the lung under the influence of a magnetic field. The results show that by changing the inlet velocity from constant to pulsatile, the drug delivery performance to the lungs increases by ∼31%. For transferring the microcarriers to the right side branches (LUL and LLL), placing the magnet at zero height and ∼30° angle yields the best outcome. Also, the microcarriers' delivery to branch LUL improves by placing the magnet at LUL-LLL bifurcation and the angle of ∼30°. It was observed that dense (9300[kgm³]) microcarriers show the best performance for delivering drugs to LLL and RLL&RML branches. Also, low-density (1000[kgm³]) microcarriers are best for delivering drugs to LUL and RUL branches. The findings of this study can improve our understanding of different factors, such as inlet velocity, the magnet's position, and the choice of microcarrier - that affect drug delivery to the infected parts of the lung.

Adsorption of Organic Dyes on Magnetic Iron Oxide Nanoparticles. Part II: Field-Induced Nanoparticle Agglomeration and Magnetic Separation

This paper (part II) is devoted to the effect of molecular adsorption on the surface of magnetic iron oxide nanoparticles (IONP) on the enhancement of their (secondary) field-induced agglomeration and magnetic separation. Experimentally, we use Methylene Blue (MB) cationic dye adsorption on citrate-coated maghemite nanoparticles to provoke primary agglomeration of IONP in the absence of the field. The secondary agglomeration is manifested through the appearance of needlelike micron-sized agglomerates in the presence of an applied magnetic field. With the increasing amount of adsorbed MB molecules, the size of the field-induced agglomerates increases and the magnetic separation on a magnetized micropillar becomes more efficient. These effects are mainly governed by the ratio of magnetic-to-thermal energy α, suspension supersaturation Δ₀, and Brownian diffusivity D_eff of primary agglomerates. The three parameters (α, Δ₀, and D_eff) are implicitly related to the surface coverage θ of IONP by MB molecules through the hydrodynamic size of primary agglomerates exponentially increasing with θ. Experiments and developed theoretical models allow quantitative evaluation of the θ effect on the efficiency of the secondary agglomeration and magnetic separation.

Magnetic systems for cancer immunotherapy

Immunotherapy is a rapidly developing area of cancer treatment due to its higher specificity and potential for greater efficacy than traditional therapies. Immune cell modulation through the administration of drugs, proteins, and cells can enhance antitumoral responses through pathways that may be otherwise inhibited in the presence of immunosuppressive tumors. Magnetic systems offer several advantages for improving the performance of immunotherapies, including increased spatiotemporal control over transport, release, and dosing of immunomodulatory drugs within the body, resulting in reduced off-target effects and improved efficacy. Compared to alternative methods for stimulating drug release such as light and pH, magnetic systems enable several distinct methods for programming immune responses. First, we discuss how magnetic hyperthermia can stimulate immune cells and trigger thermoresponsive drug release. Second, we summarize how magnetically targeted delivery of drug carriers can increase the accumulation of drugs in target sites. Third, we review how biomaterials can undergo magnetically driven structural changes to enable remote release of encapsulated drugs. Fourth, we describe the use of magnetic particles for targeted interactions with cellular receptors for promoting antitumor activity. Finally, we discuss translational considerations of these systems, such as toxicity, clinical compatibility, and future opportunities for improving cancer treatment.

Trivalent Cations Detection of Magnetic-Sensitive Microcapsules by Controlled-Release Fluorescence Off-On Sensor

A pyrene-based derivative, 2-((pyrene-1-ylmethylene)amino)ethanol (PE) nanoparticle, was encapsulated via water-in-oil-in-water (W/O/W) double emulsion with the solvent evaporation method by one-pot reaction and utilized as a fluorescence turn-on sensor for detecting Fe³⁺, Cr³⁺, and Al³⁺ ions. Magnetic nanoparticles (MNPs) embedded in polycaprolactone (PCL) were used as the magnetic-sensitive polyelectrolyte microcapsule-triggered elements in the construction of the polymer matrix. The microcapsules were characterized by ultraviolet–visible (UV–Vis) and photoluminescence (PL) titrations, quantum yield (Φ_f) calculations, ¹H nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), and superconducting quantum interference device magnetometry (SQUID) studies. This novel responsive release of the microcapsule fluorescence of the turn-on sensor for detecting trivalent cations was due to the compound PE and the MNPs being incorporated well within the whole system, and an effective thermal and kinetic energy transfer between the core and shell structure efficiently occurred in the externally oscillating magnetic field. The magnetic-sensitive fluorescence turn-on microcapsules show potential for effective metal ion sensing in environmental monitoring and even biomedical applications. Under the optimal controlled-release probe fluorescence conditions with high-frequency magnetic field treatment, the limit of detection (LOD) reached 1.574–2.860 μM and recoveries ranged from 94.7–99.4% for those metals in tap water.

Core-shell nanostructures: perspectives towards drug delivery applications

Nanosystems have shown encouraging outcomes and substantial progress in the areas of drug delivery and biomedical applications. However, the controlled and targeted delivery of drugs or genes can be limited due to their physicochemical and functional properties. In this regard, core-shell type nanoparticles are promising nanocarrier systems for controlled and targeted drug delivery applications. These functional nanoparticles are emerging as a particular class of nanosystems because of their unique advantages, including high surface area, and easy surface modification and functionalization. Such unique advantages can facilitate the use of core-shell nanoparticles for the selective mingling of two or more different functional properties in a single nanosystem to achieve the desired physicochemical properties that are essential for effective targeted drug delivery. Several types of core-shell nanoparticles, such as metallic, magnetic, silica-based, upconversion, and carbon-based core-shell nanoparticles, have been designed and developed for drug delivery applications. Keeping the scope, demand, and challenges in view, the present review explores state-of-the-art developments and advances in core-shell nanoparticle systems, the desired structure-property relationships, newly generated properties, the effects of parameter control, surface modification, and functionalization, and, last but not least, their promising applications in the fields of drug delivery, biomedical applications, and tissue engineering. This review also supports significant future research for developing multi-core and shell-based functional nanosystems to investigate nano-therapies that are needed for advanced, precise, and personalized healthcare systems.

Nanotechnology as a Platform for the Development of Injectable Parenteral Formulations: A Comprehensive Review of the Know-Hows and State of the Art

Within recent decades, the development of nanotechnology has made a significant contribution to the progress of various fields of study, including the domains of medical and pharmaceutical sciences. A substantially transformed arena within the context of the latter is the development and production of various injectable parenteral formulations. Indeed, recent decades have witnessed a rapid growth of the marketed and pipeline nanotechnology-based injectable products, which is a testimony to the remarkability of the aforementioned contribution. Adjunct to the ability of nanomaterials to deliver the incorporated payloads to many different targets of interest, nanotechnology has substantially assisted to the development of many further facets of the art. Such contributions include the enhancement of the drug solubility, development of long-acting locally and systemically injectable formulations, tuning the onset of the drug’s release through the endowment of sensitivity to various internal or external stimuli, as well as adjuvancy and immune activation, which is a desirable component for injectable vaccines and immunotherapeutic formulations. The current work seeks to provide a comprehensive review of all the abovementioned contributions, along with the most recent advances made within each domain. Furthermore, recent developments within the domains of passive and active targeting will be briefly debated.

Magnetic Graphene-Based Sheets for Bacteria Capture and Destruction Using a High-Frequency Magnetic Field

Magnetic reduced graphene oxide (MRGO) sheets were prepared by embedding Fe₃O₄ nanoparticles on polyvinylpyrrolidone (PVP) and poly(diallyldimethylammonium chloride) (PDDA)-modified graphene oxide (GO) sheets for bacteria capture and destruction under a high-frequency magnetic field (HFMF). The characteristics of MRGO sheets were evaluated systematically by transmission electron microscopy (TEM), scanning electron microscopy (SEM), zeta potential measurement, X-ray diffraction (XRD), vibrating sample magnetometry (VSM), and X-ray photoelectron spectroscopy (XPS). TEM observation revealed that magnetic nanoparticles (8–10 nm) were dispersed on MRGO sheets. VSM measurements confirmed the superparamagnetic characteristics of the MRGO sheets. Under HFMF exposure, the temperature of MRGO sheets increased from 25 to 42 °C. Furthermore, we investigated the capability of MRGO sheets to capture and destroy bacteria (Staphylococcus aureus). The results show that MRGO sheets could capture bacteria and kill them through an HFMF, showing a great potential in magnetic separation and antibacterial application.

Folic acid modified Fe3O4 nanoclusters by a one-step ultrasonic technique for drug delivery and MR imaging

Multifunctional nanoclusters based on Fe₃O₄ nanoparticles for magnetic resonance imaging (MRI) and drug delivery are reported here. At first, oleic acid (OA)-coated Fe₃O₄ nanoparticles were prepared. Then block copolymer Pluronic F127 or folic acid (FA) conjugated-Pluronic F127 was used to modify the hydrophobic nanoparticles to become hydrophilic Fe₃O₄@F127 nanoclusters via facile ultrasonic treatment. During this process, drug molecules can also be introduced into the nanoclusters and therefore the targeted drug delivery system was formed. Next, we verified the feasibility of the nanoclusters as drug delivery vehicles and magnetic contrast agents. The nanoclusters have an average size of 200 nm and remained stable in water for long periods. Folic acid-modified nanoclusters showed an enhanced intracellular uptake into HepG2 cells by using both cellular iron amount analysis and flow cytometry analysis. Besides, Fe₃O₄@F127@FA nanoclusters showed good compatibility in the tested concentration range and good sensitivity in T₂-weighted MRI. The magnetic nanoclusters combined with drug delivery properties have greatly increased the significance in the diagnosis and therapy of diseases, which are suitable for systematical administration of hydrophobic drugs and simultaneously MRI diagnosis.

Water-soluble Fe₃O₄@F127@FA nanoclusters were prepared by a facile ultrasonic-treated method for MR imaging and targeted drug delivery.

Codelivery of Hydrophobic and Hydrophilic Drugs by Graphene-Decorated Magnetic Dendrimers

In this study, a nanocarrier was prepared for the codelivery of a hydrophilic drug (doxorubicin) and a hydrophobic drug (curcumin) to cancer cells. In this nanocarrier, the edges of graphene oxide sheets were decorated with a magnetic-functionalized polyamidoamine dendrimer with hydrazone groups at the end of the polymer. The edge functionalization of graphene sheets not only improved the solubility and dispersibility of graphene sheets but also imparted the magnetic properties to the nanocarrier. The resulting nanocarrier was loaded with doxorubicin through the covalent linkage and curcumin through π-π stacking. The nanocarrier showed a pH-sensitive release for both drugs, and the drug release behavior was also improved by the coimmobilization of both drugs. The cytotoxicity assay of nanocarrier showed low toxicity toward MCF-7 cell compared to unmodified graphene oxide, which was attributed to the presence of a magnetic dendrimer. Besides, the drug-loaded nanocarrier was highly toxic for cells even more than for free drugs. The cellular uptake images revealed higher drug internalization for coloaded nanocarrier than for the nanocarrier loaded with one drug alone. All of the results showed that the codelivery of curcumin and doxorubicin in the presence of the nanocarrier was more effective in chemotherapy than the nanocarrier loaded with one drug.

Enzymatic Nanocomposites with Radio Frequency Field-Modulated Activity

The control over enzymatic activity by physical stimuli is of interest to many applications in medicine, biotechnology, synthetic biology, and nanobionics. Although the main focus has been on optically responsive systems, alternative strategies to modulate the enzymatic activity of hybrid systems are needed. Here we describe a radiofrequency (RF) field controlled catalytic activity of an enzymatic sol-gel composite. Specifically, the activity of bovine carbonic anhydrase entrapped in sol-gel-derived magnetite (enzyme@ferria) composite was accelerated by a factor of 460% compared to its initial value, by applying the RF field of 937 A/m, with fast response time. This acceleration is reversible and its magnitude controllable. An acceleration mechanism, based on RF-induced heating of the magnetite by the Néel relaxation effect, is proposed and proven. The entrapment within a sol-gel matrix solves the problem of enhancing activity by heating without denaturing the enzyme. RF-controlled enzymatic composites can be potentially applied as biological RF sensors or to control biochemical reactions within living organisms.

Disulfide bond based polymeric drug carriers for cancer chemotherapy and relevant redox environments in mammals

Increasing numbers of disulfide linkage-employing polymeric drug carriers that utilize the reversible peculiarity of this unique covalent bond have been reported. The reduction-sensitive disulfide bond is usually employed as a linkage between hydrophilic and hydrophobic polymers, polymers and drugs, or as cross-linkers in polymeric drug carriers. These polymeric drug carriers are designed to exploit the significant redox potential difference between the reducing intracellular environments and relatively oxidizing extracellular spaces. In addition, these drug carriers can release a considerable amount of anticancer drug in response to the reducing environment when they reach tumor tissues, effectively improving antitumor efficacy. This review focuses on various disulfide linkage-employing polymeric drug carriers. Important redox thiol pools, including GSH/GSSG, Cys/CySS, and Trx1, as well as redox environments in mammals, will be introduced.

Hydrophobic Drug-Loaded PEGylated Magnetic Liposomes for Drug-Controlled Release

Less targeted and limited solubility of hydrophobic-based drug are one of the serious obstacles in drug delivery system. Thus, new strategies to enhance the solubility of hydrophobic drug and controlled release behaviors would be developed. Herein, curcumin, a model of hydrophobic drug, has been loaded into PEGylated magnetic liposomes as a drug carrier platform for drug controlled release system. Inductive magnetic heating (hyperthermia)-stimulated drug release, in vitro cellular cytotoxicity assay of curcumin-loaded PEGylated magnetic liposomes and cellular internalization-induced by magnetic guidance would be investigated. The resultant of drug carriers could disperse homogeneously in aqueous solution, showing a superparamagnetic characteristic and could inductive magnetic heating with external high-frequency magnetic field (HFMF). In vitro curcumin release studies confirmed that the drug carriers exhibited no significant release at 37 °C, whereas exhibited rapid releasing at 45 °C. However, it would display enormous (three times higher) curcumin releasing under the HFMF exposure, compared with that without HFMF exposure at 45 °C. In vitro cytotoxicity test shows that curcumin-loaded PEGylated magnetic liposomes could efficiently kill MCF-7 cells in parallel with increasing curcumin concentration. Fluorescence microscopy observed that these drug carriers could internalize efficiently into the cellular compartment of MCF-7 cells. Thus, it would be anticipated that the novel hydrophobic drug-loaded PEGylated magnetic liposomes in combination with inductive magnetic heating are promising to apply in the combination of chemotherapy and thermotherapy for cancer therapy.

Injectable nanoengineered stimuli-responsive hydrogels for on-demand and localized therapeutic delivery

"Smart" hydrogels are an emerging class of biomaterials that respond to external stimuli and have been investigated for a range of biomedical applications, including therapeutic delivery and regenerative engineering. Stimuli-responsive nanogels constructed of thermoresponsive polymers such as poly(N-isopropylacrylamide-co-acrylamide) (poly(NIPAM-co-AM)) and magnetic nanoparticles (MNPs) have been developed as "smart carriers" for on-demand delivery of therapeutic biomolecules via magneto-thermal activation. However, due to their small size and systemic introduction, these poly(NIPAM-co-AM)/MNP nanogels result in limited control over long-term, localized therapeutic delivery. Here, we developed an injectable nanoengineered hydrogel loaded with poly(NIPAM-co-AM)/MNPs for localized, on-demand delivery of therapeutics (doxorubicin (DOX)). We have engineered shear-thinning and self-recoverable hydrogels by modulating the crosslinking density of a gelatin methacrylate (GelMA) network. Poly(NIPAM-co-AM)/MNP nanogels loaded with DOX were entrapped within a GelMA pre-polymer solution prior to crosslinking. The temperature and magnetic field dependent release of loaded DOX was observed from the nanoengineered hydrogels (GelMA/(poly(NIPAM-co-AM)/MNPs)). Finally, the in vitro efficacy of DOX released from injectable nanoengineered hydrogels was investigated using preosteoblast and osteosarcoma cells. Overall, these results demonstrated that the injectable nanoengineered hydrogels could be used for on-demand and localized therapeutic delivery for biomedical applications.

Drug releasing nanoplatforms activated by alternating magnetic fields

The use of an alternating magnetic field (AMF) to generate non-invasively and spatially a localized heating from a magnetic nano-mediator has become very popular these last years to develop magnetic hyperthermia (MH) as a promising therapeutic modality already used in the clinics. AMF has become highly attractive this last decade over others radiations, as AMF allows a deeper penetration in the body and a less harmful ionizing effect. In addition to pure MH which induces tumor cell death through local T elevation, this AMF-generated magneto-thermal effect can also be exploited as a relevant external stimulus to trigger a drug release from drug-loaded magnetic nanocarriers, temporally and spatially. This review article is focused especially on this concept of AMF induced drug release, possibly combined with MH. The design of such magnetically responsive drug delivery nanoplatforms requires two key and complementary components: a magnetic mediator which collects and turns the magnetic energy into local heat, and a thermoresponsive carrier ensuring thermo-induced drug release, as a consequence of magnetic stimulus. A wide panel of magnetic nanomaterials/chemistries and processes are currently developed to achieve such nanoplatforms. This review article presents a broad overview about the fundamental concepts of drug releasing nanoplatforms activated by AMF, their formulations, and their efficiency in vitro and in vivo. This article is part of a Special Issue entitled "Recent Advances in Bionanomaterials" Guest Editors: Dr. Marie-Louise Saboungi and Dr. Samuel D. Bader.

Thermo and pH dual-responsive drug-linked pseudo-polypeptide micelles with a comb-shaped polymer as a micellar exterior

The thermo and pH dual-responsive drug-linked pseudo-polypeptide micelles were prepared by a self-assembly strategy.

Injectable hydrogel-based drug delivery systems for local cancer therapy

Common chemotherapy is often associated with adverse effects in normal cells and tissues. As an alternative approach, localized chemotherapy can diminish the toxicity of systemic chemotherapy while providing a sustained release of the chemotherapeutics at the target tumor site. Therefore, injectable biodegradable hydrogels as drug delivery systems for chemotherapeutics have become a matter of importance. Here, we review the application of a variety of injectable hydrogel-based drug delivery systems, including thermosensitive, pH-sensitive, photosensitive, dual-sensitive, as well as active targeting hydrogels, for the treatment of different types of cancer. Generally, injectable hydrogel-based drug delivery systems are found to be more efficacious than the conventional systemic chemotherapy in terms of cancer treatment.

Multi-responsive hybrid particles: thermo-, pH-, photo-, and magneto-responsive magnetic hydrogel cores with gold nanorod optical triggers

The research strategy described in this manuscript harnesses the attractive properties of hydrogels, gold nanorods (Aurods), and magnetic nanoparticles (MNPs) by synthesizing one unique multi-responsive nanostructure. This novel hybrid structure consists of silica-coated magnetic particles encapsulated within a thermo-responsive P(NIPAM-co-AA) hydrogel network on which Aurods are assembled. Furthermore, this research demonstrates that these composite particles respond to several forms of external stimuli (temperature, pH, light, and/or applied magnetic field) owing to their specific architecture. Exposure of the hybrid particles to external stimuli led to a systematic and reversible variation in the hydrodynamic diameter (swelling-deswelling) and thus in the optical properties of the hybrid particles (red-shifting of the plasmon band). Such stimuli-responsive volume changes can be effectively exploited in drug-delivery applications.

Magnetic nanoparticles and nanocomposites for remote controlled therapies

This review highlights the state-of-the-art in the application of magnetic nanoparticles (MNPs) and their composites for remote controlled therapies. Novel macro- to nano-scale systems that utilize remote controlled drug release due to actuation of MNPs by static or alternating magnetic fields and magnetic field guidance of MNPs for drug delivery applications are summarized. Recent advances in controlled energy release for thermal therapy and nanoscale energy therapy are addressed as well. Additionally, studies that utilize MNP-based thermal therapy in combination with other treatments such as chemotherapy or radiation to enhance the efficacy of the conventional treatment are discussed.

Magnetically triggered nanovehicles for controlled drug release as a colorectal cancer therapy

Magnetic silica core/shell nanovehicles presenting atherosclerotic plaque-specific peptide-1 (AP-1) as a targeting ligand (MPVA-AP1 nanovehicles) have been prepared through a double-emulsion method and surface modification. Amphiphilic poly(vinyl alcohol) was introduced as a polymer binder to encapsulate various drug molecules (hydrophobic, hydrophilic, polymeric) and magnetic iron oxide (Fe3O4) nanoparticles. Under a high-frequency magnetic field, magnetic carriers (diameter: ca. 50 nm) incorporating the anti-cancer drug doxorubicin collapsed, releasing approximately 80% of the drug payload, due to the heat generated by the rapidly rotating Fe3O4 nanoparticles, thereby realizing rapid and accurate controlled drug release. Simultaneously, the magnetic Fe3O4 themselves could also kill the tumor cells through a hyperthermia effect (inductive heating). Unlike their ungrafted congeners (MPVA nanovehicles), the AP1-grafted nanovehicles bound efficiently to colorectal cancer cells (CT26-IL4Rα), thereby displaying tumor-cell selectivity. The combination of remote control, targeted dosing, drug-loading flexibility, and thermotherapy and chemotherapy suggests that magnetic nanovehicles such as MPVA-AP1 have great potential for application in cancer therapy.

Engineered Materials for Cancer Immunotherapy

Immunotherapy is a promising treatment modality for cancer as it can promote specific and durable anti-cancer responses. However, limitations to current approaches remain. Therapeutics administered as soluble injections often require high doses and frequent re-dosing, which can result in systemic toxicities. Soluble bolus-based vaccine formulations typically elicit weak cellular immune responses, limiting their use for cancer. Current methods for ex vivo T cell expansion for adoptive T cell therapies are suboptimal, and achieving high T cell persistence and sustained functionality with limited systemic toxicity following transfer remains challenging. Biomaterials can play important roles in addressing some of these limitations. For example, nanomaterials can be employed as vehicles to deliver immune modulating payloads to specific tissues, cells, and cellular compartments with minimal off-target toxicity, or to co-deliver antigen and danger signal in therapeutic vaccine formulations. Alternatively, micro-to macroscale materials can be employed as devices for controlled molecular and cellular delivery, or as engineered microenvironments for recruiting and programming immune cells in situ. Recent work has demonstrated the potential for combining cancer immunotherapy and biomaterials, and the application of biomaterials to cancer immunotherapy is likely to enable the development of effective next-generation platforms. This review discusses the application of engineered materials for the delivery of immune modulating agents to the tumor microenvironment, therapeutic cancer vaccination, and adoptive T cell therapy.

Magneto-responsive alginate capsules

Upon incorporation of magnetic nanoparticles (mNPs) into gels, composite materials called ferrogels are obtained. These magneto-responsive systems have a wide range of potential applications including switches and sensors as well as drug delivery systems. In this article, we focus on the properties of calcium alginate capsules, which are widely used as carrier systems in medicine and technology. We studied the incorporation of different kinds of mNPs in matrix capsules and in the core and the shell of hollow particles. We found out that not all particle-alginate or particle-CaCl2 solution combinations were suitable for a successful capsule preparation on grounds of a destabilization of the nanoparticles or the polymer. For those systems allowing the preparation of switchable beads or capsules, we systematically studied the size and microscopic structure of the capsules, their magnetic behavior and mechanical resistance.

Recent progress in biomedical applications of Pluronic (PF127): Pharmaceutical perspectives

Most of the administered anti-cancer drugs are hydrophobic in nature and are known to have poor water solubility, short residence time, rapid clearance from the body and systemic side effects. Polymeric-based targeted particulate carrier system has shown to directly deliver the encapsulated anti-cancer drug to the desired site of action and prevent the interaction of encapsulated drug with the normal cells. Pluronic F127 (PF127) has been widely investigated for its broad-range of therodiagnostic applications in biomedical and pharmaceutical sciences, but rapid dissolution in the physiological fluids, short residence time, rapid clearance, and weak mechanical strength are the main shortcomings that are associated with PF127 and have recently been overcome by making various modifications in the structure of PF127 notably through preparation of PF127-based mixed polymeric micelles, PF127-conjugated nanoparticles and PF127-based hydrophobically modified thermogels. In this article, we have briefly discussed the recent studies that have been conducted on various anti-cancer drugs using PF127 as nano-carrier modified with other copolymers and/or conjugated with magnetic nanoparticles. The key findings of these studies demonstrated that the modified form of PF127 can significantly increase the stability of incorporated hydrophobic drugs with enhanced in vitro cytotoxicity and cellular uptake of anti-cancer drugs. Moreover, the modified form of PF127 has also shown its therapeutic potentials as therodiagnostics in various types of tumors and cancers. Hence, it can be concluded that the modified form of PF127 exhibits significant therodiagnostic effects with increased tumor-specific delivery of anti-cancer drugs having minimal toxic effects as compared to PF127 alone and/or other copolymers.

Design of hybrid nanovehicles for remotely triggered drug release: an overview

This review addresses the advantages of remote triggers, e.g. ultrasounds, near infrared light and alternating magnetic fields, the fabrication of the hybrid nanovehicles, the release mechanisms and the next challenges.

Magnetic nanoparticles-loaded PLA/PEG microspheres as drug carriers

Surface-modified magnetite (Fe3 O4 ) nanoparticles with an average size of 22 nm were prepared. The nanoparticles had a saturation magnetization of 50.7 emu g(-1) . Then magnetite and drug-loaded microspheres of poly (lactic acid)/poly (ethylene glycol) were prepared at various compositions. The microspheres were spherical in shape and had smooth surface. The diameter size of the microspheres ranged between about 0.2 and 4 μm. Doxorubicin hydrochloride for cancer treatment was the drug that loaded into the microspheres. The prepared microspheres were characterized by FTIR, XRD, VSM, SEM and drug-release measurements. It was found that the drug cumulative release percentage was proportional to (time) (n) where 0.61 < n < 0.75 depending on PEG and Fe3 O4 contents. The drug release was controlled through a combination of diffusion and PLA hydrolysis and obeyed a non-fickian mechanism. The drug release was facilitated by presence of poly (ethylene glycol) as PLA plasticizer and was higher under applied external magnetic field. The obtained magnetic microspheres could be used as drug carriers for targeted drug delivery purposes.

Graphene oxide–Fe3O4 nanocomposite for combination of dual-drug chemotherapy with photothermal therapy

A graphene oxide–Fe₃O₄ nanocomposite against drug-resistant tumors by the combination of dual-drug chemotherapy and photothermal therapy with NIR.

Magnetic liposomes for colorectal cancer cells therapy by high-frequency magnetic field treatment

In this study, we developed the cancer treatment through the combination of chemotherapy and thermotherapy using doxorubicin-loaded magnetic liposomes. The citric acid-coated magnetic nanoparticles (CAMNP, ca. 10 nm) and doxorubicin were encapsulated into the liposome (HSPC/DSPE/cholesterol = 12.5:1:8.25) by rotary evaporation and ultrasonication process. The resultant magnetic liposomes (ca. 90 to 130 nm) were subject to characterization including transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray diffraction (XRD), zeta potential, Fourier transform infrared (FTIR) spectrophotometer, and fluorescence microscope. In vitro cytotoxicity of the drug carrier platform was investigated through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay using L-929 cells, as the mammalian cell model. In vitro cytotoxicity and hyperthermia (inductive heating) studies were evaluated against colorectal cancer (CT-26 cells) with high-frequency magnetic field (HFMF) exposure. MTT assay revealed that these drug carriers exhibited no cytotoxicity against L-929 cells, suggesting excellent biocompatibility. When the magnetic liposomes with 1 μM doxorubicin was used to treat CT-26 cells in combination with HFMF exposure, approximately 56% cells were killed and found to be more effective than either hyperthermia or chemotherapy treatment individually. Therefore, these results show that the synergistic effects between chemotherapy (drug-controlled release) and hyperthermia increase the capability to kill cancer cells.

Self-assembly behaviors of thermal- and pH- sensitive magnetic nanocarriers for stimuli-triggered release

In the present work, we prepare thermo- and pH-sensitive polymer-based nanoparticles incorporating with magnetic iron oxide as the remote-controlled, stimuli-response nanocarriers. Well-defined, dual functional tri-block copolymer poly[(acrylic acid)-block-(N-isopropylacrylamide)-block-(acrylic acid)], was synthesized via reversible addition-fragmentation chain-transfer (RAFT) polymerization with S,S'-bis(α,α'-dimethyl-α″-acetic acid)trithiocarbonate (CMP) as a chain transfer agent (CTA). With the aid of using 3-aminopropyltriethoxysilane, the surface-modified iron oxides, Fe3O4-NH2, was then attached on the surface of self-assembled tri-block copolymer micelles via 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride/N-hydroxysuccinamide (EDC/NHS) crosslinking method in order to furnish not only the magnetic resources for remote control but also the structure maintenance for spherical morphology of our nanocarriers. The nanocarrier was characterized by transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR), and ultraviolet-visible (UV/Vis) spectral analysis. Rhodamine 6G (R6G), as the modeling drugs, was encapsulated into the magnetic nanocarriers by a simple swelling method for fluorescence-labeling and controlled release monitoring. Biocompatibility of the nanocarriers was studied via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, which revealed that neither the pristine nanocarrier nor the R6G-loaded nanocarriers were cytotoxic to the normal fibroblast cells (L-929 cells). The in vitro stimuli-triggered release measurement showed that the intelligent nanocarriers were highly sensitive to the change of pH value and temperature rising by the high-frequency magnetic field (HFMF) treatment, which provided the significant potential to apply this technology to biomedical therapy by stimuli-responsive controlled release.

Development of Magnetic Nanoparticles for Cancer Gene Therapy: A Comprehensive Review

Since they were first proposed as nonviral transfection agents for their gene-carrying capacity, magnetic nanoparticles have been studied thoroughly, both in vitro and in vivo. Great effort has been made to manufacture biocompatible magnetic nanoparticles for use in the theragnosis of cancer and other diseases. Here we survey recent advances in the study of magnetic nanoparticles, as well as the polymers and other coating layers currently available for gene therapy, their synthesis, and bioconjugation processes. In addition, we review several gene therapy models based on magnetic nanoparticles.

Fabrication of polymer nanocapsules with controllable oligo(ethylene glycol) densities, permeation properties and robustly crosslinked walls

P(TMSPMA-co-OEGMA) nanocapsules with controllable oligo(ethylene glycol) (OEG) densities and robustly cross-linked structures were successfully fabricated from the cross-linkable copolymer, poly[3-(trimethoxysilyl)propyl methacrylate-co-oligo(ethylene glycol) methacrylate] (P(TMSPMA-co-OEGMA)). The densities of OEG segments of the resultant P(TMSPMA-co-OEGMA) nanocapsules could be easily controlled by tuning the OEGMA contents of copolymer P(TMSPMA-co-OEGMA). The microenvironments of the P(TMSPMA-co-OEGMA) nanocapsules were determined to be hydrophobic. It was demonstrated that hydrophobic pyrene could be in situ loaded into the P(TMSPMA-co-OEGMA) nanocapsules during the fabrication procedure. The release rates of pyrene from the P(TMSPMA-co-OEGMA) nanocapsules were dependent on the contents of OEGMA, indicating that the permeation properties of P(TMSPMA-co-OEGMA) nanocapsules could be tuned by varying the cross-linked densities of the nanocapsule walls. It was further demonstrated that other functional groups could be easily incorporated into the resultant polymer nanocapsules by using the similar procedure. The preparation of polymer nanocapsules with various functionalities and robustly cross-linked walls without any further post modification process, any sacrificial core and surfactant would be beneficial from scientific and technical point of views.