Multifunctional and Stimuli-Responsive Magnetic Nanoparticle-Based Delivery Systems for Biomedical Applications

NucleoCraft: The Art of Stimuli-Responsive Precision in DNA and RNA Bioengineering

Recent advancements in DNA and RNA bioengineering have paved the way for developing stimuli-responsive nanostructures with remarkable potential across various applications. These nanostructures, crafted through sophisticated bioengineering techniques, can dynamically and precisely respond to both physiological and physical stimuli, including nucleic acids (DNA/RNA), adenosine triphosphate, proteins, ions, small molecules, pH, light, and temperature. They offer high sensitivity and specificity, making them ideal for applications such as biomarker detection, gene therapy, and controlled targeted drug delivery. In this review, we summarize the bioengineering methods used to assemble versatile stimuli-responsive DNA/RNA nanostructures and discuss their emerging applications in structural biology and biomedicine, including biosensing, targeted drug delivery, and therapeutics. Finally, we highlight the challenges and opportunities in the rational design of these intelligent bioengineered nanostructures.

Integrated design and application of stimuli-responsive metal-organic frameworks in biomedicine: current status and future perspectives

In recent years, metal-organic frameworks (MOFs) have garnered widespread attention due to their distinctive attributes, such as high surface area, tunable properties, biodegradability, extremely low density, high loading capacity, diverse chemical functionalities, thermal stability, well-defined pore sizes, and molecular dimensions. Increasingly, biomedical researchers have turned their focus towards their multifaceted development. Among these, stimuli-responsive MOFs, with their unique advantages, have captured greater interest from researchers. This review will delve into the merits and drawbacks of both endogenous and exogenous stimuli-responsive MOFs, along with their application directions. Furthermore, it will outline the characteristics of different synthesis routes of MOFs, exploring various design schemes and modification strategies and their impacts on the properties of MOF products, as well as how to control them. Additionally, we will survey different types of stimuli-responsive MOFs, discussing the significance of various MOF products reported in biomedical applications. We will categorically summarize different strategies such as anticancer therapy, antibacterial treatment, tissue repair, and biomedical imaging, as well as insights into the development of novel MOFs nanomaterials in the future. Finally, this review will conclude by summarizing the challenges in the development of stimuli-responsive MOFs in the field of biomedicine and providing prospects for future research endeavors.

Smart nanoparticles for cancer therapy

Smart nanoparticles, which can respond to biological cues or be guided by them, are emerging as a promising drug delivery platform for precise cancer treatment. The field of oncology, nanotechnology, and biomedicine has witnessed rapid progress, leading to innovative developments in smart nanoparticles for safer and more effective cancer therapy. In this review, we will highlight recent advancements in smart nanoparticles, including polymeric nanoparticles, dendrimers, micelles, liposomes, protein nanoparticles, cell membrane nanoparticles, mesoporous silica nanoparticles, gold nanoparticles, iron oxide nanoparticles, quantum dots, carbon nanotubes, black phosphorus, MOF nanoparticles, and others. We will focus on their classification, structures, synthesis, and intelligent features. These smart nanoparticles possess the ability to respond to various external and internal stimuli, such as enzymes, pH, temperature, optics, and magnetism, making them intelligent systems. Additionally, this review will explore the latest studies on tumor targeting by functionalizing the surfaces of smart nanoparticles with tumor-specific ligands like antibodies, peptides, transferrin, and folic acid. We will also summarize different types of drug delivery options, including small molecules, peptides, proteins, nucleic acids, and even living cells, for their potential use in cancer therapy. While the potential of smart nanoparticles is promising, we will also acknowledge the challenges and clinical prospects associated with their use. Finally, we will propose a blueprint that involves the use of artificial intelligence-powered nanoparticles in cancer treatment applications. By harnessing the potential of smart nanoparticles, this review aims to usher in a new era of precise and personalized cancer therapy, providing patients with individualized treatment options.

Oxygen-Generating Organic/Inorganic Self-Assembled Nanocolloids for Tumor-Activated Dual-Model Imaging-Guided Photodynamic Therapy

Tumor phototheranostics is usually compromised by the hypoxic tumor microenvironment and poor theranostic efficiency. The interplay between organic polymers and inorganic nanoparticles in novel nanocomposites has proven to be advantageous, overcoming previous limitations and harnessing their full potential through activation via the tumor microenvironment. This study successfully fabricated hypoxia-activated nanocolloids called HOISNDs through a process of self-assembly involving superparamagnetic iron oxide nanoparticles (SPIONs) and an organic polymer ligand called tetrakis(4-carboxyphenyl) porphyrin (TCPP)-engineered organic polymer ligand [methoxy poly(ethyleneglycol)-block-poly(dopamine-ethylenediamine-conjugated-4-nitrobenzyl chloroformate)-l-glutamate, mPEG-b-P(Dopa-EDA-co-NBCF)LG-TCPP)]. The SPIONs act as an oxygen generator to overcome the challenges posed by hypoxic tumors and enable the use of hypoxic-activatable MR/fluorescence dual-modal imaging-guided photodynamic therapy (PDT). The colloid stability of these HOISNDs proved to be exceptional in diverse biomimetic environments. Furthermore, they not only augment T₂-weighted contrast capability as an MRI contrast agent but also function as an oxygen-producing device to amplify the generation and release of reactive oxygen species (ROS). The HOISNDs can significantly target to tumor sites through the enhanced permeability and retention (EPR) effect with prolonged blood circulation time and subsequently are effectively endocytosed into a hypoxic intracellular environment that "turn on" the imaging function and photodynamic activity. Moreover, HOISNDs possess the ability to effectively decompose naturally occurring H₂O₂ into oxygen (O₂) within the tumor utilizing the Fenton reaction. This method can mitigate the impact of hypoxia on oxygen-dependent PDT. The outcomes of in vivo diagnostic and therapeutic evaluations indicated that HOISNDs are a highly promising tool for dual-model imaging-guided cancer theranosis by ameliorating hypoxic conditions and augmenting PDT efficiency.

Synthetic molecular motor activates drug delivery from polymersomes

The design of stimuli-responsive systems in nanomedicine arises from the challenges associated with the unsolved needs of current molecular drug delivery. Here, we present a delivery system with high spatiotemporal control and tunable release profiles. The design is based on the combination of an hydrophobic synthetic molecular rotary motor and a PDMS-b-PMOXA diblock copolymer to create a responsive self-assembled system. The successful incorporation and selective activation by low-power visible light (λ = 430 nm, 6.9 mW) allowed to trigger the delivery of a fluorescent dye with high efficiencies (up to 75%). Moreover, we proved the ability to turn on and off the responsive behavior on demand over sequential cycles. Low concentrations of photoresponsive units (down to 1 mol% of molecular motor) are shown to effectively promote release. Our system was also tested under relevant physiological conditions using a lung cancer cell line and the encapsulation of an Food and Drug Administration (FDA)-approved drug. Similar levels of cell viability are observed compared to the free given drug showing the potential of our platform to deliver functional drugs on request with high efficiency. This work provides an important step for the application of synthetic molecular machines in the next generation of smart delivery systems.

Multilayer Methacrylate-Based Wound Dressing as a Therapeutic Tool for Targeted Pain Relief

This study presents an innovative wound dressing system that offers a highly effective therapeutic solution for treating painful wounds. By incorporating the widely used non-steroidal anti-inflammatory drug diclofenac, we have created an active wound dressing that can provide targeted pain relief with ease. The drug was embedded within a biocompatible matrix composed of polyhydroxyethyl methacrylate and polyhydroxypropyl methacrylate. The multilayer structure of the dressing, which allows for sustained drug release and an exact application, was achieved through the layer-by-layer coating technique and the inclusion of superparamagnetic iron platinum nanoparticles. The multilayered dressings' physicochemical, structural, and morphological properties were characterised using various methods. The synergistic effect of the incorporated drug molecules and superparamagnetic nanoparticles on the surface roughness and release kinetics resulted in controlled drug release. In addition, the proposed multilayer wound dressings were found to be biocompatible with human skin fibroblasts. Our findings suggest that the developed wound dressing system can contribute to tailored therapeutic strategies for local pain relief.

Recent Advances in Targeted Nanocarriers for the Management of Triple Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a life-threatening form of breast cancer which has been found to account for 15% of all the subtypes of breast cancer. Currently available treatments are significantly less effective in TNBC management because of several factors such as poor bioavailability, low specificity, multidrug resistance, poor cellular uptake, and unwanted side effects being the major ones. As a rapidly growing field, nano-therapeutics offers promising alternatives for breast cancer treatment. This platform provides a suitable pathway for crossing biological barriers and allowing sustained systemic circulation time and an improved pharmacokinetic profile of the drug. Apart from this, it also provides an optimized target-specific drug delivery system and improves drug accumulation in tumor cells. This review provides insights into the molecular mechanisms associated with the pathogenesis of TNBC, along with summarizing the conventional therapy and recent advances of different nano-carriers for the management of TNBC.

A review on the recent progress, opportunities, and challenges of 4D printing and bioprinting in regenerative medicine

Four-dimensional (4 D) printing is a novel emerging technology, which can be defined as the ability of 3 D printed materials to change their form and functions. The term 'time' is added to 3 D printing as the fourth dimension, in which materials can respond to a stimulus after finishing the manufacturing process. 4 D printing provides more versatility in terms of size, shape, and structure after printing the construct. Complex material programmability, multi-material printing, and precise structure design are the essential requirements of 4 D printing systems. The utilization of stimuli-responsive polymers has increasingly taken the place of cell traction force-dependent methods and manual folding, offering a more advanced technique to affect a construct's adjusted shape transformation. The present review highlights the concept of 4 D printing and the responsive bioinks used in 4 D printing, such as water-responsive, pH-responsive, thermo-responsive, and light-responsive materials used in tissue regeneration. Cell traction force methods are described as well. Finally, this paper aims to introduce the limitations and future trends of 4 D printing in biomedical applications based on selected key references from the last decade.

Therapeutic Applications of Magnetotactic Bacteria and Magnetosomes: A Review Emphasizing on the Cancer Treatment

Magnetotactic bacteria (MTB) are aquatic microorganisms have the ability to biomineralize magnetosomes, which are membrane-enclosed magnetic nanoparticles. Magnetosomes are organized in a chain inside the MTB, allowing them to align with and traverse along the earth’s magnetic field. Magnetosomes have several potential applications for targeted cancer therapy when isolated from the MTB, including magnetic hyperthermia, localized medication delivery, and tumour monitoring. Magnetosomes features and properties for various applications outperform manufactured magnetic nanoparticles in several ways. Similarly, the entire MTB can be regarded as prospective agents for cancer treatment, thanks to their flagella’s ability to self-propel and the magnetosome chain’s ability to guide them. MTBs are conceptualized as nanobiots that can be guided and manipulated by external magnetic fields and are driven to hypoxic areas, such as tumor sites, while retaining the therapeutic and imaging characteristics of isolated magnetosomes. Furthermore, unlike most bacteria now being studied in clinical trials for cancer treatment, MTB are not pathogenic but might be modified to deliver and express certain cytotoxic chemicals. This review will assess the current and prospects of this burgeoning research field and the major obstacles that must be overcome before MTB can be successfully used in clinical treatments.

Functionalized hybrid magnetic catalytic systems on micro- and nanoscale utilized in organic synthesis and degradation of dyes

Herein, a concise review of the latest developments in catalytic processes involving organic reactions is presented, focusing on magnetic catalytic systems (MCSs). In recent years, various micro- and nanoscale magnetic catalysts have been prepared through different methods based on optimized reaction conditions and utilized in complex organic synthesis or degradation reactions of pharmaceutical compounds. These biodegradable, biocompatible and eco-benign MCSs have achieved the principles of green chemistry, and thus their usage is highly advocated. In addition, MCSs can shorten the reaction time, effectively accelerate reactions, and significantly upgrade both pharmaceutical synthesis and degradation mechanisms by preventing unwanted side reactions. Moreover, the other significant benefits of MCSs include their convenient magnetic separation, high stability and reusability, inexpensive raw materials, facile preparation routes, and surface functionalization. In this review, our aim is to present at the recent improvements in the structure of versatile MCSs and their characteristics, i.e., magnetization, recyclability, structural stability, turnover number (TON), and turnover frequency (TOF). Concisely, different hybrid and multifunctional MCSs are discussed. Additionally, the applications of MCSs for the synthesis of different pharmaceutical ingredients and degradation of organic wastewater contaminants such as toxic dyes and drugs are demonstrated.

Transport of Magnetic Polyelectrolyte Capsules in Various Environments

Microcapsules consisting of eleven layers of polyelectrolyte and one layer of iron oxide nanoparticles were fabricated. Two types of nanoparticles were inserted as one of the layers within the microcapsule’s walls: Fe2O3, ferric oxide, having a mean diameter (Ø) of 50 nm and superparamagnetic Fe3O4 having Ø 15 nm. The microcapsules were suspended in liquid environments at a concentration of 108 caps/mL. The suspensions were pumped through a tube over a permanent magnet, and the accumulation within a minute was more than 90% of the initial concentration. The design of the capsules, the amount of iron embedded in the microcapsule, and the viscosity of the transportation fluid had a rather small influence on the accumulation capacity. Magnetic microcapsules have broad applications from cancer treatment to molecular communication.

Design of Smart Size-, Surface-, and Shape-Switching Nanoparticles to Improve Therapeutic Efficacy

Multiple biological barriers must be considered in the design of nanomedicines, including prolonged blood circulation, efficient accumulation at the target site, effective penetration into the target tissue, selective uptake of the nanoparticles into target cells, and successful endosomal escape. However, different particle sizes, surface chemistries, and sometimes shapes are required to achieve the desired transport properties at each step of the delivery process. In response, this review highlights recent developments in the design of switchable nanoparticles whose size, surface chemistry, shape, or a combination thereof can be altered as a function of time, a disease-specific microenvironment, and/or via an externally applied stimulus to enable improved optimization of nanoparticle properties in each step of the delivery process. The practical use of such nanoparticles in chemotherapy, bioimaging, photothermal therapy, and other applications is also discussed.

Magnetic Fields and Cancer: Epidemiology, Cellular Biology, and Theranostics

Humans are exposed to a complex mix of man-made electric and magnetic fields (MFs) at many different frequencies, at home and at work. Epidemiological studies indicate that there is a positive relationship between residential/domestic and occupational exposure to extremely low frequency electromagnetic fields and some types of cancer, although some other studies indicate no relationship. In this review, after an introduction on the MF definition and a description of natural/anthropogenic sources, the epidemiology of residential/domestic and occupational exposure to MFs and cancer is reviewed, with reference to leukemia, brain, and breast cancer. The in vivo and in vitro effects of MFs on cancer are reviewed considering both human and animal cells, with particular reference to the involvement of reactive oxygen species (ROS). MF application on cancer diagnostic and therapy (theranostic) are also reviewed by describing the use of different magnetic resonance imaging (MRI) applications for the detection of several cancers. Finally, the use of magnetic nanoparticles is described in terms of treatment of cancer by nanomedical applications for the precise delivery of anticancer drugs, nanosurgery by magnetomechanic methods, and selective killing of cancer cells by magnetic hyperthermia. The supplementary tables provide quantitative data and methodologies in epidemiological and cell biology studies. Although scientists do not generally agree that there is a cause-effect relationship between exposure to MF and cancer, MFs might not be the direct cause of cancer but may contribute to produce ROS and generate oxidative stress, which could trigger or enhance the expression of oncogenes.

Structural analysis of an iron-assisted carbon monolayer for delivery of 2-thiouracil

An idea of employing an iron-assisted carbon (FeC) monolayer for delivery of 2-thiouracil (2TU) was examined in this work by analyzing structural features for singular and bimolecular models. Density functional theory (DFT) calculations were performed for optimizing the structures and evaluating molecular and atomic descriptors for analyzing the models systems. Two bimolecular models were obtained assigning by S-FeC and O-FeC models, in which each of S and O atom of 2TU was relaxed towards the Fe region of FeC surface in the mentioned models, respectively. The results indicated that both models were achievable with slightly more favorability for formation of S-FeC model. The obtained molecular orbital properties revealed the dominant role of FeC monolayer for managing future interactions of attached 2TU, which is indeed a major role for employing nanomaterials for targeted drug delivery purposes. In addition to energies and molecular orbital features, atomic quadrupole coupling constants indicated the benefit of employing FeC monolayer for drug delivery of 2TU.

External stimuli-responsive nanoparticles for spatially and temporally controlled delivery of CRISPR-Cas genome editors

The CRISPR-Cas9 system is a powerful tool for genome editing, which can potentially lead to new therapies for genetic diseases. To date, various viral and non-viral delivery systems have been developed for the delivery of CRISPR-Cas9 in vivo. However, spatially and temporally controlled genome editing is needed to enhance the specificity in organs/tissues and minimize the off-target effects of editing. In this review, we summarize the state-of-the-art non-viral vectors that exploit external stimuli (i.e., light, magnetic field, and ultrasound) for spatially and temporally controlled genome editing and their in vitro and in vivo applications.

Smart Nanomaterials for Treatment of Biofilm in Orthopedic Implants

Biofilms refer to complex bacterial communities that are attached to the surface of animate or inanimate objects, which highly resist the antibiotics or the host immune defense mechanisms. Pathogenic biofilms in medicine are general, chronic, and even costly, especially on medical devices and orthopedic implants. Bacteria within biofilms are the cause of many persistent infections, which are almost impossible to eradicate. Though some progress has been made in comprehending the mechanisms of biofilm formation and persistence, novel alternative compounds or strategies and effective anti-biofilm antibiotics are still lacking. Smart materials of nano size which are able to respond to an external stimulus or internal environment have a great range of applications in clinic. Recently, smart nanomaterials with or without carriage of antibiotics, targeting specific bacteria and biofilm under some stimuli, have shown great potential for pathogenic biofilm and resident bacteria eradication. First, this review briefly summarizes and describes the significance of biofilms and the process of biofilm formation. Then, we focus on some of the latest research studies involving biofilm elimination, which probably could be applied in orthopedic implants. Finally, some outstanding challenges and limitations that need to be settled urgently in order to make smart nanomaterials effectively target and treat implant biofilms are also discussed. It is hoped that there will be more novel anti-biofilm strategies for biofilm infection in the prospective future.

Advanced biomedical applications of iron oxide nanostructures based ferrofluids

Ferrofluids or magnetic nanofluids are highly stable colloidal suspensions of magnetic nanoparticles (NPs) dispersed into various base fluids. These stable ferrofluids possess high thermal conductivity, improved thermo-physical properties, higher colloidal stability, good magnetic properties, and biocompatibility, which are the primary driving forces behind their excellent performance, and thus enable them to be used for a wide range of practical applications. The most studied and advanced ferrofluids are based on iron oxide nanostructures especially NPs, because of their easy and large-scale synthesis at low costs. Although in the last decade, several review articles are available on ferrofluids but mainly focused on preparations, properties, and a specific application. Hence, a collective and comprehensive review article on the recent progress of iron oxide nanostructures based ferrofluids for advanced biomedical applications is undeniably required. In this review, the state of the art of biomedical applications is presented and critically analyzed with a special focus on hyperthermia, drug delivery/nanomedicine, magnetic resonance imaging, and magnetic separation of cells. This review article provides up-to-date information related to the technological advancements and emerging trends in iron oxide nanostructures based ferrofluids research focused on advanced biomedical applications. Finally, conclusions and outlook of iron oxide nanostructures based ferrofluids research for biomedical applications are presented.

Nanogel-facilitated Protein Intracellular Specific Degradation through Trim-Away

Recently discovered "Trim-Away" mechanism opens a new window for fast and selective degradation of endogenous proteins. However, the in vivo and clinical application of this approach is stuck by the requirement of special skills and equipment needed for the intracellular delivery of antibodies. Hereby, an antibody conjugated polymer nanogel system, Nano-ERASER, for intracellular delivery and release of antibody, and degradation of a specific endogenous protein has been developed. After being delivered into cells, the antibody is released and forms complex with its target protein, and subsequently binds to the Fc receptor of TRIM21. The resulted complex of target protein/antibody/TRIM21 is then degraded by the proteasome. The efficacy of Nano-ERASER has been validated by depleting GFP protein in a GFP expressing cell line. Furthermore, Nano-ERASER successfully degrades COPZ1, a vital protein for cancer cells, and kills those cells while sparing normal cells. Benefit from its convenience and targeted delivery merit, Nano-ERASER technique is promising in providing a reliable tool for endogenous protein function study as well as paves the way for novel antibody-based Trim-Away therapeutic modalities for cancer and other diseases.

Microfluidic platform for synthesis and optimization of chitosan-coated magnetic nanoparticles in cisplatin delivery

In this study, magnetic core/chitosan shell Nanoparticles (NPs) containing cisplatin were synthesized via cisplatin complexation with tripolyphosphate as the chitosan crosslinker using two different procedures: a conventional batch flow method and a microfluidic approach. An integrated microfluidic device composed of three stages was developed to provide precise and highly controllable mixing. The comparison of the results revealed that NPs synthesized in microchannels were monodisperse 104 ± 14.59 nm (n = 3) in size with optimal morphological characteristics, whereas polydisperse 423 ± 53.33 nm (n = 3) nanoparticles were obtained by the conventional method. Furthermore, cisplatin was loaded in NPs without becoming inactivated, and the microfluidic technique demonstrated higher encapsulation efficiency, controlled release, and consequently lower IC50 values during exposure to the A2780 cell line proving that microfluidic synthesized NPs were able to enter the cells and release the drug more efficiently. The developed microfluidic platform presents valuable features that could potentially provide the clinical translation of NPs in drug delivery.

Stimulus-Responsive Nanoparticle Magnetic Resonance Imaging Contrast Agents: Design Considerations and Applications

Magnetic resonance imaging (MRI) has been widely used for disease diagnosis because it can noninvasively obtain anatomical details of various diseases through accurate contrast between soft tissues. Over one-third of MRI examinations are performed with the assistance of contrast agents. Traditional contrast agents typically display an unchanging signal, thus exhibiting relatively low sensitivity and poor specificity. Currently, advances in stimulus-responsive contrast agents which can alter the relaxation signal in response to a specific change in their surrounding environment provide new opportunities to overcome such limitation. The signal changes based on stimulus also reflects the physiological and pathological conditions of the site of interests. In this review, how to design stimulus-responsive nanoparticle MRI contrast agents from the perspective of theory and surface design is comprehensively discussed. Key structural features including size, clusters, shell features, and surface properties are used for tuning the T₁ and T₂ relaxation properties. The reversible or non-reversible signal changes highlight the contrast agents have undergone structural changes based on certain stimulus, as an indication for disease diagnosis or therapeutic efficacy.

3 4 - Cysteine -

In this research, a facile, two-step synthesis of Fe₃O₄–L_Cysteine–graphene quantum dots (GQDs) nanocomposite is reported. This synthesis method comprises the preparation of GQDs via hydrothermal route, which should be conjugated to the L_Cysteine functionalized core–shell magnetic structure with the core of about 7.5-nm iron oxide nanoparticle and 3.5-nm L_Cysteine shell. L_Cysteine, as a biocompatible natural amino acid, was used to link magnetite nanoparticles (MNPs) with GQDs. X-ray powder diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray were used to investigate the presence and formation of MNPs, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{L}}_{{{\text{Cysteine}}}}$$\end{document}LCysteine functionalized MNPs, and final hybrid nanostructure. Morphology and size distribution of nanoparticles were demonstrated by scanning electron microscopy and transmission electron microscopy. Finally, the magnetic and optical properties of the prepared nanocomposite were measured by vibrating sample magnetometer, ultraviolet–visible, and photoluminescence spectroscopy. The results show that Fe₃O₄–L_Cysteine–GQDs nanocomposite exhibits a superparamagnetic behavior at room temperature with high saturation magnetization and low magnetic coercivity, which are 28.99 emu/g and 0.09 Oe, respectively. This nanocomposite also shows strong and stable emission at 460 nm and 530 nm when it is excited with the 235 nm wavelength. The magnetic GQDs structure also reveals the absorption wavelength at 270 nm. Therefore, Fe₃O₄–L_Cysteine–GQDs nanocomposite can be considered as a potential multifunctional hybrid structure with magnetic and optical properties simultaneously. This nanocomposite can be used for a wide range of biomedical applications like magnetic resonance imaging (MRI) contrast agents, biosensors, photothermal therapy, and hyperthermia.

Dual activatable self-assembled nanotheranostics for bioimaging and photodynamic therapy

Multifunctional nanosystems that can transport therapeutic and diagnostic agents into tumor sites and activate their respective functions via tumor-microenvironment recognition are highly desirable for clinical applications. We fabricated pH and redox dual-activatable self-assembled nanotheranostics (named as DA-SNs) via coordination-driven self-assembly of chlorin e6 (Ce6) disulfide-linked pH sensitive polymer ligand, poly (isobutylene-alt-maleic anhydride-graft-methoxy-poly (ethyleneglycol)-graft-imidazole-graft-Cystamine-Ce6) [PIMA-mPEG-API-SS-Ce6], and gadolinium ions (Gd³⁺). DA-SNs exhibited uniform particle size of ~48 nm, excellent stability, and inherent biosafety. Negatively charged DA-SNs could prolong blood circulation time (t_1/2 = 2.91 h) and improve tumor accumulation. Moreover, DA-SNs could undergo surface charge switch from negative charge to positive one in a slightly acidic tumor extracellular environment (pH 6.8), thus enhancing cellular uptake. After entering tumor cells, fluorescence, photodynamic therapeutic activity, and T₁MR contrast from DA-SNs could be activated within this intracellular environment with lowered pH and high level of GSH. Importantly, human tumors implanted in mice could be successfully visualized via distinct pH and redox dual-sensitive T₁MR contrast and fluorescence imaging, indicating that DA-SNs could serve as a dual-modal MR/fluorescence imaging probe for tumor-targeting diagnosis. In addition, DA-SNs exhibited superior photodynamic therapeutic efficiency with negligible side effects. Therefore, this DA-SN shows great promise for synergistic photodynamic therapy and diagnostic imaging.

Size-Tunable Metal-Organic Framework-Coated Magnetic Nanoparticles for Enzyme Encapsulation and Large-Substrate Biocatalysis

Immobilizing enzymes on nanoparticles (NPs) enhances the cost-efficiency of biocatalysis; however, when the substrates are large, it becomes difficult to separate the enzyme@NP from the products while avoiding leaching or damage of enzymes in the reaction medium. Metal-organic framework (MOF)-coated magnetic NPs (MNPs) offer efficient magnetic separation and enhanced enzyme protection; however, the involved enzymes/substrates have to be smaller than the MOF apertures. A potential solution to these challenges is coprecipitating metal/ligand with enzymes on the MNP surface, which can partially bury (protect) the enzyme below the composite surface while exposing the rest of the enzyme to the reaction medium for catalysis of larger substrates. Here, to prove this concept, we show that using Ca²⁺ and terephthalic acid (BDC), large-substrate enzymes can be encapsulated in CaBDC-MOF layers coated on MNPs via an enzyme-friendly, aqueous-phase one-pot synthesis. Interestingly, we found that using MNPs as the nuclei of crystallization, the composite size can be tuned so that nanoscale composites were formed under low Ca²⁺/BDC concentrations, while microscale composites were formed under high Ca²⁺/BDC concentrations. While the microscale composites showed significantly enhanced reusability against a non-structured large substrate, the nanoscale composites displayed enhanced catalytic efficiency against a rigid, crystalline-like large substrate, starch, likely due to the improved diffusivity of the nanoscale composites. To our best knowledge, this is the first report on aqueous-phase one-pot synthesis of size-tunable enzyme@MOF/MNP composites for large-substrate biocatalysis. Our platform can be applied to immobilize other large-substrate enzymes with enhanced reusability and tunable sizes.

Stimuli-Responsive Nanomaterials for Application in Antitumor Therapy and Drug Delivery

The new era of nanotechnology has produced advanced nanomaterials applicable to various fields of medicine, including diagnostic bio-imaging, chemotherapy, targeted drug delivery, and biosensors. Various materials are formed into nanoparticles, such as gold nanomaterials, carbon quantum dots, and liposomes. The nanomaterials have been functionalized and widely used because they are biocompatible and easy to design and prepare. This review mainly focuses on nanomaterials responsive to the external stimuli used in drug-delivery systems. To overcome the drawbacks of conventional therapeutics to a tumor, the dual- and multi-responsive behaviors of nanoparticles have been harnessed to improve efficiency from a drug delivery point of view. Issues and future research related to these nanomaterial-based stimuli sensitivities and the scope of stimuli-responsive systems for nanomedicine applications are discussed.

Stimuli-Responsive Materials for Tissue Engineering and Drug Delivery

Smart or stimuli-responsive materials are an emerging class of materials used for tissue engineering and drug delivery. A variety of stimuli (including temperature, pH, redox-state, light, and magnet fields) are being investigated for their potential to change a material's properties, interactions, structure, and/or dimensions. The specificity of stimuli response, and ability to respond to endogenous cues inherently present in living systems provide possibilities to develop novel tissue engineering and drug delivery strategies (for example materials composed of stimuli responsive polymers that self-assemble or undergo phase transitions or morphology transformations). Herein, smart materials as controlled drug release vehicles for tissue engineering are described, highlighting their potential for the delivery of precise quantities of drugs at specific locations and times promoting the controlled repair or remodeling of tissues.

Tailor-made legumain/pH dual-responsive doxorubicin prodrug-embedded nanoparticles for efficient anticancer drug delivery and in situ monitoring of drug release

Legumain enzyme is a well-conserved lysosomal cysteine protease and is over-expressed in many tumor cells and tumor stromal cells and exhibits higher protease activity under acidic conditions, such as in lysosomes and endosomes. Legumain enzyme-triggered drug delivery systems have demonstrated potential therapeutic values in cancer targeted therapy. To realize a more efficient delivery of anticancer therapeutic agents, we herein report a legumain/pH dual-responsive drug delivery system for enhancing site-specific controlled release of antitumor drugs. The carrier (named "DS-NA") is a hybrid vector constituting PEG-b-PBLA polymers, pH-responsive OAPI polymers, and legumain-sensitive peptide-doxorubicin prodrug decorated fluorescent carbon dots (CDs-C9-AANL-DOX). In tumor cells, DS-NA could disassemble rapidly in acidic environments, and then release doxorubicin through legumain digestion. Except as a drug vector, the drug release process from DS-NA could also be dynamically monitored by CLSM as the DOX was released from the surface of CDs through the AANL peptide linker digested by legumain, then transferred into the cell nucleus and exerted cytotoxicity, while the CDs themselves remained in the cytoplasm. As a control, the CDs-C9-DOX, which did not contain the AANL peptide linker, also still resided in the cytoplasm. Furthermore, in vivo studies show that DS-NA had a stronger inhibitory effect on tumor tissue with attenuated side effects to normal tissues than control nanoparticles or free drugs, which may be due to comprehensive effects including pH/legumain dual-triggered drug release, long blood circulation periods, and EPR effects. Together, a combination strategy of acid sensitivity and legumain enzyme sensitivity used for site-specific controlled release of drugs provides a novel method for enhanced and precise antitumor chemotherapy.

The Role of Magnetic Nanoparticles in Cancer Nanotheranostics

Technological development is in constant progress in the oncological field. The search for new concepts and strategies for improving cancer diagnosis, treatment and outcomes constitutes a necessary and continuous process, aiming at more specificity, efficiency, safety and better quality of life of the patients throughout the treatment. Nanotechnology embraces these purposes, offering a wide armamentarium of nanosized systems with the potential to incorporate both diagnosis and therapeutic features, towards real-time monitoring of cancer treatment. Within the nanotechnology field, magnetic nanosystems stand out as complex and promising nanoparticles with magnetic properties, that enable the use of these constructs for magnetic resonance imaging and thermal therapy purposes. Additionally, magnetic nanoparticles can be tailored for increased specificity and reduced toxicity, and functionalized with contrast, targeting and therapeutic agents, revealing great potential as multifunctional nanoplatforms for application in cancer theranostics. This review aims at providing a comprehensive description of the current designs, characterization techniques, synthesis methods, and the role of magnetic nanoparticles as promising nanotheranostic agents. A critical appraisal of the impact, potentialities and challenges associated with each technology is also presented.

Magnetic nanoparticles in nanomedicine: a review of recent advances

Nanomaterials, in addition to their small size, possess unique physicochemical properties that differ from bulk materials, making them ideal for a host of novel applications. Magnetic nanoparticles (MNPs) are one important class of nanomaterials that have been widely studied for their potential applications in nanomedicine. Due to the fact that MNPs can be detected and manipulated by remote magnetic fields, it opens a wide opportunity for them to be used in vivo. Nowadays, MNPs have been used for diverse applications including magnetic biosensing (diagnostics), magnetic imaging, magnetic separation, drug and gene delivery, and hyperthermia therapy, etc. Specifically, we reviewed some emerging techniques in magnetic diagnostics such as magnetoresistive (MR) and micro-Hall (μHall) biosensors, as well as the magnetic particle spectroscopy, magnetic relaxation switching and surface enhanced Raman spectroscopy (SERS)-based bioassays. Recent advances in applying MNPs as contrast agents in magnetic resonance imaging and as tracer materials in magnetic particle imaging are reviewed. In addition, the development of high magnetic moment MNPs with proper surface functionalization has progressed exponentially over the past decade. To this end, different MNP synthesis approaches and surface coating strategies are reviewed and the biocompatibility and toxicity of surface functionalized MNP nanocomposites are also discussed. Herein, we are aiming to provide a comprehensive assessment of the state-of-the-art biological and biomedical applications of MNPs. This review is not only to provide in-depth insights into the different synthesis, biofunctionalization, biosensing, imaging, and therapy methods but also to give an overview of limitations and possibilities of each technology.

CURATE.AI: Optimizing Personalized Medicine with Artificial Intelligence

The clinical team attending to a patient upon a diagnosis is faced with two main questions: what treatment, and at what dose? Clinical trials' results provide the basis for guidance and support for official protocols that clinicians use to base their decisions upon. However, individuals rarely demonstrate the reported response from relevant clinical trials, often the average from a group representing a population or subpopulation. The decision complexity increases with combination treatments where drugs administered together can interact with each other, which is often the case. Additionally, the individual's response to the treatment varies over time with the changes in his or her condition, whether via the indication or physiology. In practice, the drug and the dose selection depend greatly on the medical protocol of the healthcare provider and the medical team's experience. As such, the results are inherently varied and often suboptimal. Big data approaches have emerged as an excellent decision-making support tool, but their application is limited by multiple challenges, the main one being the availability of sufficiently big datasets with good quality, representative information. An alternative approach-phenotypic personalized medicine (PPM)-finds an appropriate drug combination (quadratic phenotypic optimization platform [QPOP]) and an appropriate dosing strategy over time (CURATE.AI) based on small data collected exclusively from the treated individual. PPM-based approaches have demonstrated superior results over the current standard of care. The side effects are limited while the desired output is maximized, which directly translates into improving the length and quality of individuals' lives.

Therapeutic efficacy of nanoparticles and routes of administration

In modern-day medicine, nanotechnology and nanoparticles are some of the indispensable tools in disease monitoring and therapy. The term “nanomaterials” describes materials with nanoscale dimensions (< 100 nm) and are broadly classified into natural and synthetic nanomaterials. However, “engineered” nanomaterials have received significant attention due to their versatility. Although enormous strides have been made in research and development in the field of nanotechnology, it is often confusing for beginners to make an informed choice regarding the nanocarrier system and its potential applications. Hence, in this review, we have endeavored to briefly explain the most commonly used nanomaterials, their core properties and how surface functionalization would facilitate competent delivery of drugs or therapeutic molecules. Similarly, the suitability of carbon-based nanomaterials like CNT and QD has been discussed for targeted drug delivery and siRNA therapy. One of the biggest challenges in the formulation of drug delivery systems is fulfilling targeted/specific drug delivery, controlling drug release and preventing opsonization. Thus, a different mechanism of drug targeting, the role of suitable drug-laden nanocarrier fabrication and methods to augment drug solubility and bioavailability are discussed. Additionally, different routes of nanocarrier administration are discussed to provide greater understanding of the biological and other barriers and their impact on drug transport. The overall aim of this article is to facilitate straightforward perception of nanocarrier design, routes of various nanoparticle administration and the challenges associated with each drug delivery method.

Synthesis, Bioapplications, and Toxicity Evaluation of Chitosan-Based Nanoparticles

The development of advanced nanomaterials and technologies is essential in biomedical engineering to improve the quality of life. Chitosan-based nanomaterials are on the forefront and attract wide interest due to their versatile physicochemical characteristics such as biodegradability, biocompatibility, and non-toxicity, which play a promising role in biological applications. Chitosan and its derivatives are employed in several applications including pharmaceuticals and biomedical engineering. This article presents a comprehensive overview of recent advances in chitosan derivatives and nanoparticle synthesis, as well as emerging applications in medicine, tissue engineering, drug delivery, gene therapy, and cancer therapy. In addition to the applications, we critically review the main concerns and mitigation strategies related to chitosan bactericidal properties, toxicity/safety using tissue cultures and animal models, and also their potential environmental impact. At the end of this review, we also provide some of future directions and conclusions that are important for expanding the field of biomedical applications of the chitosan nanoparticles.

Polymers, responsiveness and cancer therapy

A single outcome in a biological procedure at the time of cancer therapy is due to multiple changes happening simultaneously. Hence to mimic such complex biological processes, an understanding of stimuli responsiveness is needed to sense specific changes and respond in a predictable manner. Such responses due to polymers may take place either simultaneously at the site or in a sequential manner from preparation to transporting pathways to cellular compartments. The present review comprehends the stimuli-responsive polymers and multi-responsiveness with respect to cancer therapy. It focuses on the exploitation of different stimuli like temperature, pH and enzymes responsiveness in a multi-stimuli setting. Nanogels and micelles being two of the most commonly used responsive polymeric carriers have also been discussed. The role of multiple stimuli delivery system is significant due to multiple changes happening in the near surroundings of cancer cells. These responsive materials are able to mimic some biological processes and recognize at the molecular level itself to manipulate development of custom-designed molecules for targeting cancer cells.

Nanocapsules for Programmed Neurotransmitter Release: Toward Artificial Extracellular Synaptic Vesicles

Nanocapsules present a promising platform for delivering chemicals and biomolecules to a site of action in a living organism. Because the biological action of the encapsulated molecules is blocked until they are released from the nanocapsules, the encapsulation structure enables triggering of the topical and timely action of the molecules at the target site. A similar mechanism seems promising for the spatiotemporal control of signal transduction triggered by the release of signal molecules in neuronal, metabolic, and immune systems. From this perspective, nanocapsules can be regarded as practical tools to apply signal molecules such as neurotransmitters to intervene in signal transduction. However, spatiotemporal control of the payload release from nanocapsules persists as a key technical issue. Stimulus-responsive nanocapsules that release payloads in response to external input of physical stimuli are promising platforms to enable programmed payload release. These programmable nanocapsules encapsulating neurotransmitters are expected to lead to new insights and perspectives related to artificial extracellular synaptic vesicles that might provide an experimental and therapeutic strategy for neuromodulation and nervous system disorders.

Artificial intelligence in nanomedicine

The field of nanomedicine has made substantial strides in the areas of therapeutic and diagnostic development. For example, nanoparticle-modified drug compounds and imaging agents have resulted in markedly enhanced treatment outcomes and contrast efficiency. In recent years, investigational nanomedicine platforms have also been taken into the clinic, with regulatory approval for Abraxane® and other products being awarded. As the nanomedicine field has continued to evolve, multifunctional approaches have been explored to simultaneously integrate therapeutic and diagnostic agents onto a single particle, or deliver multiple nanomedicine-functionalized therapies in unison. Similar to the objectives of conventional combination therapy, these strategies may further improve treatment outcomes through targeted, multi-agent delivery that preserves drug synergy. Also, similar to conventional/unmodified combination therapy, nanomedicine-based drug delivery is often explored at fixed doses. A persistent challenge in all forms of drug administration is that drug synergy is time-dependent, dose-dependent and patient-specific at any given point of treatment. To overcome this challenge, the evolution towards nanomedicine-mediated co-delivery of multiple therapies has made the potential of interfacing artificial intelligence (AI) with nanomedicine to sustain optimization in combinatorial nanotherapy a reality. Specifically, optimizing drug and dose parameters in combinatorial nanomedicine administration is a specific area where AI can actionably realize the full potential of nanomedicine. To this end, this review will examine the role that AI can have in substantially improving nanomedicine-based treatment outcomes, particularly in the context of combination nanotherapy for both N-of-1 and population-optimized treatment.

Enhancing Antitumor Efficacy by Simultaneous ATP-Responsive Chemodrug Release and Cancer Cell Sensitization Based on a Smart Nanoagent

The exploitation of smart nanoagents based drug delivery systems (DDSs) has proven to be a promising strategy for fighting cancers. Hitherto, such nanoagents still face challenges associated with their complicated synthesis, insufficient drug release in tumors, and low cancer cell chemosensitivity. Here, the engineering of an adenosine triphosphate (ATP)-activatable nanoagent is demonstrated based on self-assembled quantum dots-phenolic nanoclusters to circumvent such challenges. The smart nanoagent constructed through a one-step assembly not only has high drug loading and low cytotoxicity to normal cells, but also enables ATP-activated disassembly and controlled drug delivery in cancer cells. Particularly, the nanoagent can induce cell ATP depletion and increase cell chemosensitivity for significantly enhanced cancer chemotherapy. Systematic in vitro and in vivo studies further reveal the capabilities of the nanoagent for intracellular ATP imaging, high tumor accumulation, and eventual body clearance. As a result, the presented multifunctional smart nanoagent shows enhanced antitumor efficacy by simultaneous ATP-responsive chemodrug release and cancer cell sensitization. These findings offer new insights toward the design of smart nanoagents for improved cancer therapeutics.