Biological Fate of Magnetic Protein-Specific Molecularly Imprinted Polymers: Toxicity and Degradation

Gelatin-based carbon quantum dot-molecularly imprinted polymer: Safe photoluminescent core-shell nano-carrier for the pH-responsive anticancer drug delivery

This study aims to synthesize a core-shell gelatin-based carbon quantum dot-molecularly imprinted polymer (MIP@g-CQD) via the precipitation free-radical polymerization process using methotrexate (MTX) as a model anticancer template. To investigate the efficiency of the prepared photoluminescent MIP@g-CQD as a pH-responsive nano-carrier, MTX was loaded into MIP@g-CQD by soaking in a drug solution and the release behavior of the loaded drug was evaluated in the necessary pH values (7.4, 5). The successful synthesis of materials was characterized using PL, TEM, FE-SEM, DLS, and FT-IR analyses. Interestingly, the created cavities in the core-shell nano-carriers can interact with the MTX molecules effectively, leading to an increase in the loading capacity. According to the obtained results from Langmuir adsorption isotherms, the imprinting factor was calculated (IF = 4.91). Also, the binding kinetics of MTX revealed the creation of particular recognition sites in the core-shell polymeric network. The MTX-loaded MIP@g-CQD displayed a low rate and limited release at the simulated physiological environment (pH 7.4, 37 °C), but it is increased at tumor tissue (pH 5, 41 °C) conditions, which can lead to long-term and sustained release of MTX in the desired target. This property of MIP@g-CQD could avoid the release of MTX in normal physiological conditions, decreasing the possible side effects of MTX drug. Owing to the existence of amide functional groups in the nano-carrier structure and its negatively charged nature, the MTT assay displayed desirable cytotoxicity against the breast cancer cell line (MCF-7) for the MTX-loaded nano-carrier. According to the obtained results, the prepared safe photoluminescent MIP@g-CQD with appropriate pH-responsivity has a high ability to be applied as an anticancer and bio-detection agent.

Biodegradation by Cancer Cells of Magnetite Nanoflowers with and without Encapsulation in PS-b-PAA Block Copolymer Micelles

Magnetomicelles were produced by the self-assembly of magnetite iron oxide nanoflowers and the amphiphilic poly(styrene)-b-poly(acrylic acid) block copolymer to deliver a multifunctional theranostic agent. Their bioprocessing by cancer cells was investigated in a three-dimensional spheroid model over a 13-day period and compared with nonencapsulated magnetic nanoflowers. A degradation process was identified and monitored at various scales, exploiting different physicochemical fingerprints. At a collective level, measurements were conducted using magnetic, photothermal, and magnetic resonance imaging techniques. At the nanoscale, transmission electron microscopy was employed to identify the morphological integrity of the structures, and X-ray absorption spectroscopy was used to analyze the degradation at the crystalline phase and chemical levels. All of these measurements converge to demonstrate that the encapsulation of magnetic nanoparticles in micelles effectively mitigates their degradation compared to individual nonencapsulated magnetic nanoflowers. This protective effect consequently resulted in better maintenance of their therapeutic photothermal potential. The structural degradation of magnetomicelles occurred through the formation of an oxidized iron phase in ferritin from the magnetic nanoparticles, leaving behind empty spherical polymeric ghost shells. These results underscore the significance of encapsulation of iron oxides in micelles in preserving nanomaterial integrity and regulating degradation, even under challenging physicochemical conditions within cancer cells.

Recent trends in preparation and biomedical applications of iron oxide nanoparticles

The iron oxide nanoparticles (IONPs), possessing both magnetic behavior and semiconductor property, have been extensively used in multifunctional biomedical fields due to their biocompatible, biodegradable and low toxicity, such as anticancer, antibacterial, cell labelling activities. Nevertheless, there are few IONPs in clinical use at present. Some IONPs approved for clinical use have been withdrawn due to insufficient understanding of its biomedical applications. Therefore, a systematic summary of IONPs' preparation and biomedical applications is crucial for the next step of entering clinical practice from experimental stage. This review summarized the existing research in the past decade on the biological interaction of IONPs with animal/cells models, and their clinical applications in human. This review aims to provide cutting-edge knowledge involved with IONPs' biological effects in vivo and in vitro, and improve their smarter design and application in biomedical research and clinic trials.

Molecularly Imprinted Carriers for Diagnostics and Therapy-A Critical Appraisal

Simultaneous diagnostics and targeted therapy provide a theranostic approach, an instrument of personalized medicine-one of the most-promising trends in current medicine. Except for the appropriate drug used during the treatment, a strong focus is put on the development of effective drug carriers. Among the various materials applied in the production of drug carriers, molecularly imprinted polymers (MIPs) are one of the candidates with great potential for use in theranostics. MIP properties such as chemical and thermal stability, together with capability to integrate with other materials are important in the case of diagnostics and therapy. Moreover, the MIP specificity, which is important for targeted drug delivery and bioimaging of particular cells, is a result of the preparation process, conducted in the presence of the template molecule, which often is the same as the target compound. This review focused on the application of MIPs in theranostics. As a an introduction, the current trends in theranostics are described prior to the characterization of the concept of molecular imprinting technology. Next, a detailed discussion of the construction strategies of MIPs for diagnostics and therapy according to targeting and theranostic approaches is provided. Finally, frontiers and future prospects are presented, stating the direction for further development of this class of materials.

Biodegradable and Sustainable Synthetic Antibodies-A Perspective

Molecular imprinting technology has been around for almost a century, and we have witnessed dramatic advancements in the overall design and production of molecularly imprinted polymers (MIPs), particularly in terms of possible formats of the final products when it comes to truly resembling antibody substitutes, i.e., MIP nanoparticles (MIP NPs). Nonetheless, the overall technology appears to struggle to keep up with the current global sustainability efforts, as recently elucidated in the latest comprehensive reviews, which introduced the "GREENIFICATION" concept. In this review, we will try to elucidate if these advancements in MIP nanotechnology have indeed resulted in a sustainability amelioration. We will do so by discussing the general production and purification strategies for MIP NPs, specifically from a sustainability and biodegradation perspective, also considering the final intended application and ultimate waste management.

Real-Time Monitoring of Neurotransmitters in the Brain of Living Animals

Neurotransmitters, as important chemical small molecules, perform the function of neural signal transmission from cell to cell. Excess concentrations of neurotransmitters are often closely associated with brain diseases, such as Alzheimer's disease, depression, schizophrenia, and Parkinson's disease. On the other hand, the release of neurotransmitters under the induced stimulation indicates the occurrence of reward-related behaviors, including food and drug addiction. Therefore, to understand the physiological and pathological functions of neurotransmitters, especially in complex environments of the living brain, it is urgent to develop effective tools to monitor their dynamics with high sensitivity and specificity. Over the past 30 years, significant advances in electrochemical sensors and optical probes have brought new possibilities for studying neurons and neural circuits by monitoring the changes in neurotransmitters. This Review focuses on the progress in the construction of sensors for in vivo analysis of neurotransmitters in the brain and summarizes current attempts to address key issues in the development of sensors with high selectivity, sensitivity, and stability. Combined with the latest advances in technologies and methods, several strategies for sensor construction are provided for recording chemical signal changes in the complex environment of the brain.

Assessing the In Vivo Biocompatibility of Molecularly Imprinted Polymer Nanoparticles

Molecularly imprinted polymer nanoparticles (nanoMIPs) are high affinity synthetic receptors which show promise as imaging and therapeutic agents. Comprehensive analysis of the in vivo behaviour of nanoMIPs must be performed before they can be considered for clinical applications. This work reports the solid-phase synthesis of nanoMIPs and an investigation of their biodistribution, clearance and cytotoxicity in a rat model following both intravenous and oral administration. These nanoMIPs were found in each harvested tissue type, including brain tissue, implying their ability to cross the blood-brain barrier. The nanoMIPs were cleared from the body via both faeces and urine. Furthermore, we describe an immunogenicity study in mice, demonstrating that nanoMIPs specific for a cell surface protein showed moderate adjuvant properties, whilst those imprinted for a scrambled peptide showed no such behaviour. Given their ability to access all tissue types and their relatively low cytotoxicity, these results pave the way for in vivo applications of nanoMIPs.

Greenificated Molecularly Imprinted Materials for Advanced Applications

Molecular imprinting technology (MIT) produces artificial binding sites with precise complementarity to substrates and thereby is capable of exquisite molecular recognition. Over five decades of evolution, it is predicted that the resulting host imprinted materials will overtake natural receptors for research and application purposes, but in practice, this has not yet been realized due to the unsustainability of their life cycles (i.e., precursors, creation, use, recycling, and end-of-life). To address this issue, greenificated molecularly imprinted polymers (GMIPs) are a new class of plastic antibodies that have approached sustainability by following one or more of the greenification principles, while also demonstrating more far-reaching applications compared to their natural counterparts. In this review, the most recent developments in the delicate design and advanced application of GMIPs in six fast-growing and emerging fields are surveyed, namely biomedicine/therapy, catalysis, energy harvesting/storage, nanoparticle detection, gas sensing/adsorption, and environmental remediation. In addition, their distinct features are highlighted, and the optimal means to utilize these features for attaining incredibly far-reaching applications are discussed. Importantly, the obscure technical challenges of the greenificated MIT are revealed, and conceivable solutions are offered. Lastly, several perspectives on future research directions are proposed.

How Molecularly Imprinted Polymers can be Used for Diagnostic and Treatment of Tropical Diseases?

Molecularly imprinted polymers (MIPs) have been widely used in nanomedicine in the last few years. However, their use for diagnostic and treatment of tropical diseases is limited. Through this review, we aim to illustrate how MIPs were used to detect tropical disease and we show that they are not exploited enough in treatment. We finally show how MIPs could be used in the future in the treatment of tropical disease.

Biotinylated magnetic molecularly imprinted polymer nanoparticles for cancer cell targeting and controlled drug delivery

Here, multivalent functions have been successfully integrated on a single core-shell type nanostructure, for remote-controlled and receptor-targeted intracellular delivery of doxorubicin (DOX) to breast cancer cells that overexpress biotin receptors.

Hybrid Molecularly Imprinted Polymers: The Future of Nanomedicine?

Molecularly imprinted polymers (MIPs) have been widely used in nanomedicine in the last few years. However, their potential is limited by their intrinsic properties resulting, for instance, in lack of control in drug release processes or complex detection for in vivo imaging. Recent attempts in creating hybrid nanomaterials combining MIPs with inorganic nanomaterials succeeded in providing a wide range of new interesting properties suitable for nanomedicine. Through this review, we aim to illustrate how hybrid molecularly imprinted polymers may improve patient care with enhanced imaging, treatments, and a combination of both.

Molecular Imprinting: Green Perspectives and Strategies

Advances in revolutionary technologies pose new challenges for human life; in response to them, global responsibility is pushing modern technologies toward greener pathways. Molecular imprinting technology (MIT) is a multidisciplinary mimic technology simulating the specific binding principle of enzymes to substrates or antigens to antibodies; along with its rapid progress and wide applications, MIT faces the challenge of complying with green sustainable development requirements. With the identification of environmental risks associated with unsustainable MIT, a new aspect of MIT, termed green MIT, has emerged and developed. However, so far, no clear definition has been provided to appraise green MIT. Herein, the implementation process of green chemistry in MIT is demonstrated and a mnemonic device in the form of an acronym, GREENIFICATION, is proposed to present the green MIT principles. The entire greenificated imprinting process is surveyed, including element choice, polymerization implementation, energy input, imprinting strategies, waste treatment, and recovery, as well as the impacts of these processes on operator health and the environment. Moreover, assistance of upgraded instrumentation in deploying greener goals is considered. Finally, future perspectives are presented to provide a more complete picture of the greenificated MIT road map and to pave the way for further development.

Ever-Evolving Identity of Magnetic Nanoparticles within Human Cells: The Interplay of Endosomal Confinement, Degradation, Storage, and Neocrystallization

Considerable knowledge has been acquired in inorganic nanoparticles' synthesis and nanoparticles' potential use in biomedical applications. Among different materials, iron oxide nanoparticles remain unrivaled for several reasons. Not only do they respond to multiple physical stimuli (e.g., magnetism, light) and exert multifunctional therapeutic and diagnostic actions but also they are biocompatible and integrate endogenous iron-related metabolic pathways. With the aim to optimize the use of (magnetic) iron oxide nanoparticles in biomedicine, different biophysical phenomena have been recently identified and studied. Among them, the concept of a "nanoparticle's identity" is of particular importance. Nanoparticles' identities evolve in distinct biological environments and over different periods of time. In this Account, we focus on the remodeling of magnetic nanoparticles' identities following their journey inside cells. For instance, nanoparticles' functions, such as heat generation or magnetic resonance imaging, can be highly impacted by endosomal confinement. Structural degradation of nanoparticles was also evidenced and quantified in cellulo and correlates with the loss of magnetic nanoparticle properties. Remarkably, in human stem cells, the nonmagnetic products of nanoparticles' degradation could be subsequently reassembled into neosynthesized, endogenous magnetic nanoparticles. This stunning occurrence might account for the natural presence of magnetic particles in human organs, especially the brain. However, mechanistic details and the implication of such phenomena in homeostasis and disease have yet to be completely unraveled.This Account aims to assess the short- and long-term transformations of magnetic iron oxide nanoparticles in living cells, particularly focusing on human stem cells. Precisely, we herein overview the multiple and ever-evolving chemical, physical, and biological magnetic nanoparticles' identities and emphasize the remarkable intracellular fate of these nanoparticles.

Photoresponsive Surface Molecularly Imprinted Polymers for the Detection of Profenofos in Tomato and Mangosteen

As a moderately toxic organophosphorus pesticide, profenofos (PFF) is widely used in agricultural practice, resulting in the accumulation of a high amount of PFF in agricultural products and the environment. This will inevitably damage our health. Therefore, it is important to establish a convenient and sensitive method for the detection of PFF. This paper reports a photoresponsive surface-imprinted polymer based on poly(styrene-co-methyl acrylic acid) (PS-co-PMAA@PSMIPs) for the detection of PFF by using carboxyl-capped polystyrene microspheres (PS-co-PMAA), PFF, 4-((4-(methacryloyloxy)phenyl)diazenyl) benzoic acid, and triethanolamine trimethacrylate as the substrate, template, functional monomer, and cross-linker, respectively. PS-co-PMAA@PSMIP shows good photoresponsive properties in DMSO/H2O (3:1, v/v). Its photoisomerization rate constant exhibits a good linear relationship with PFF concentration in the range of 0~15 μmol/L. PS-co-PMAA@PSMIP was applied for the determination of PFF in spiked tomato and mangosteen with good recoveries ranging in 94.4-102.4%.

Protein Component of Oyster Glycogen Nanoparticles: An Anchor Point for Functionalization

Biosourced nanoparticles have a range of desirable properties for therapeutic applications, including biodegradability and low immunogenicity. Glycogen, a natural polysaccharide nanoparticle, has garnered much interest as a component of advanced therapeutic materials. However, functionalizing glycogen for use as a therapeutic material typically involves synthetic approaches that can negatively affect the intrinsic physiological properties of glycogen. Herein, the protein component of glycogen is examined as an anchor point for the photopolymerization of functional poly(N-isopropylacrylamide) (PNIPAM) polymers. Oyster glycogen (OG) nanoparticles partially degrade to smaller spherical particles in the presence of protease enzymes, reflecting a population of surface-bound proteins on the polysaccharide. The grafting of PNIPAM to the native protein component of OG produces OG-PNIPAM nanoparticles of ∼45 nm in diameter and 6.2 MDa in molecular weight. PNIPAM endows the nanoparticles with temperature-responsive aggregation properties that are controllable and reversible and that can be removed by the biodegradation of the protein. The OG-PNIPAM nanoparticles retain the native biodegradability of glycogen. Whole blood incubation assays revealed that the OG-PNIPAM nanoparticles have a low cell association and inflammatory response similar to that of OG. The reported strategy provides functionalized glycogen nanomaterials that retain their inherent biodegradability and low immune cell association.

Developments of Smart Drug-Delivery Systems Based on Magnetic Molecularly Imprinted Polymers for Targeted Cancer Therapy: A Short Review

Cancer therapy is still a huge challenge, as especially chemotherapy shows several drawbacks like low specificity to tumor cells, rapid elimination of drugs, high toxicity and lack of aqueous solubility. The combination of molecular imprinting technology with magnetic nanoparticles provides a new class of smart hybrids, i.e., magnetic molecularly imprinted polymers (MMIPs) to overcome limitations in current cancer therapy. The application of these complexes is gaining more interest in therapy, due to their favorable properties, namely, the ability to be guided and to generate slight hyperthermia with an appropriate external magnetic field, alongside the high selectivity and loading capacity of imprinted polymers toward a template molecule. In cancer therapy, using the MMIPs as smart-drug-delivery robots can be a promising alternative to conventional direct administered chemotherapy, aiming to enhance drug accumulation/penetration into the tumors while fewer side effects on the other organs. Overview: In this review, we state the necessity of further studies to translate the anticancer drug-delivery systems into clinical applications with high efficiency. This work relates to the latest state of MMIPs as smart-drug-delivery systems aiming to be used in chemotherapy. The application of computational modeling toward selecting the optimum imprinting interaction partners is stated. The preparation methods employed in these works are summarized and their attainment in drug-loading capacity, release behavior and cytotoxicity toward cancer cells in the manner of in vitro and in vivo studies are stated. As an essential issue toward the development of a body-friendly system, the biocompatibility and toxicity of the developed drug-delivery systems are discussed. We conclude with the promising perspectives in this emerging field. Areas covered: Last ten years of publications (till June 2020) in magnetic molecularly imprinted polymeric nanoparticles for application as smart-drug-delivery systems in chemotherapy.