Dual responsive molecularly imprinted polymers based on UiO-66-DOX for selective targeting tumor cells and controlled drug release

Theranostic advances and the role of molecular imprinting in disease management

Molecular imprinting has become an effective technology in the realm of diagnosing diseases, providing unparalleled specificity and sensitivity. This method is a promising trend in current medical research. This review examines the utilization of molecularly imprinted polymers (MIPs) in theranostic that integrates diagnostic functionalities for personalized medicine. The present work briefly discusses the fundamental concepts of molecular imprinting and how it has evolved into a versatile platform. Subsequently, the utilization of MIPs in the advancement of biosensors is focused, specifically emphasizing their contribution to the detection and diagnosis of diseases. The therapeutic potential of MIPs, focusing on targeted drug delivery and controlled release systems and the integration of MIPs into theranostic platforms is explored through case studies, showcasing the technology's ability to simultaneously diagnose and treat diseases. Finally, we address the current challenges facing MIPs and discuss future perspectives, emphasizing the potential of this technology to revolutionize the next generation.

Stimuli-Responsive Molecularly Imprinted Polymers: Mechanism and Applications

Molecularly imprinted polymers (MIPs) are very suitable for extraction, drug delivery systems, and sensors due to their good selective adsorption ability, but the difficulty of eluting templates during synthesis and the limitation of application scenarios put higher demands on MIPs. Stimuli-responsive MIPs (SR-MIPs) can actively respond to changes in external conditions to realize various functions, which provides new ideas for the further development of MIPs. This paper reviews the multiple response modes of MIPs, including the common temperature, pH, photo, magnetic, redox-responsive and rare gas, biomolecule, ion, and solvent-responsive MIPs, and explains the mechanism, composition, and applications of such SR-MIPs. These SR-MIPs and the resulting dual/multiple-responsive MIPs have good selectivity, and controllability, and are very promising for isolation and extraction, targeted drug delivery, and electro-sensor.

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.

Design of pH-responsive molecularly imprinted polymer as a carrier for controlled and sustainable capecitabine release

A molecularly imprinting polymer (MIP) carrier with pH-responsivity was designed to construct a drug delivery system (DDS) focusing on controlled and sustainable capecitabine (CAPE) release. The pH-responsive characteristic was achieved by the functionalization of SiO2 substrate with 4-formylphenylboronic acid, accompanied by the introduction of fluorescein isothiocyanate for the visualization of the intracellular localization of the nanocarrier. Experimental results indicated that CAPE was adsorbed onto the drug carrier with satisfactory encapsulation efficiency. The controlled release of CAPE was realized based on the break of borate ester bonds between -B(OH)2 and cis-diols in the weakly acidic environment. Density functional theory computations were conducted to investigate the adsorption/release mechanism. Moreover, in vitro experiments confirmed the good biocompatibility and ideal inhibition efficiency of the developed DDS. The MIP can act as an eligible carrier and exhibits the great potential in practical applications for tumor treatment.

Fundamentals, Synthetic Strategies and Applications of Non-Covalently Imprinted Polymers

Molecular imprinting has emerged as an important and practical technology to create economical and stable synthetic mimics of antibodies and enzymes. It has already found a variety of important applications, such as affinity separation, chemical/biological sensing, disease diagnostics, proteomics, bioimaging, controlled drug release, and catalysis. In the past decade, significant breakthroughs have been made in non-covalently imprinted polymers, from their synthesis through to their applications. In terms of synthesis, quite a few versatile and facile imprinting approaches for preparing MIPs have been invented, which have effectively solved some key issues in molecular imprinting. Additionally, important applications in several areas, such as sensors, proteomics and bioimaging, have been well demonstrated. In this review, we critically and comprehensively survey key recent advances made in the preparation of non-covalently imprinted polymers and their important applications. We focus on the state-of-art of this technology from three different perspectives: fundamentals, synthetic strategies, and applications. We first provide a fundamental basis for molecular imprinting technologies that have been developed, which is extremely helpful for establishing a sound understanding of the challenges in molecular imprinting. Then, we discuss in particular the major breakthroughs within the last ten years (2014-2024), with emphasis on new imprinting approaches, what strengths the breakthroughs can provide, and which new applications the properties of the prepared non-covalently imprinted polymers are fit for.

Molecularly Imprinted Polymeric Nanoparticles as Drug Delivery System for Tenofovir, an Acyclic Nucleoside Phosphonate Antiviral

A molecularly imprinted polymer of Tenofovir (1), an FDA-approved acyclic nucleoside phosphonate with antiviral activity, was synthesized using a non-covalent approach. A pre-polymerization complex was formed between (1) and DMAEMA and in-house synthetic N1-[(2-methacryloyloxy)ethyl] thymine, with EGDMA as a cross-linker in an MeCN/H2O (9:1, 1:1) mixture as a porogen, giving an imprinting factor (IF) of 5.5 at 2.10-5 mol/L. Binding parameters were determined by the Freundlich-Langmuir model, Qmax and Ka, and well as the particle morphology for MIP and NIP. Finally, the release profiles, for MIP and NIP, were obtained at 25 °C and 37 °C, which is body temperature, in a phosphate buffer saline, pH 7.4, mimicking the blood pH value, to determine the potential sustained release of our polymeric materials.

Novel molecularly imprinted aerogels: Preparation, characterization, and application in selective separation for oleanolic acid in lingonberry

An oleanolic acid (OA) surface molecularly imprinted polymer silylated porous composite aerogels (OA-MIP@Si-PC-aerogels) adsorbent material was successfully prepared and characterized. The material not only has a great selectivity for the target molecule OA but also has other noteworthy qualities including high stability, excellent repeatability, and a sizable adsorption capacity. via cellulose and sodium alginate as the main materials, the carrier Si-PC-aerogels were made through ionic cross-linking, chemical cross-linking, and silylation procedures. By adopting a surface molecular imprinting approach on Si-PC-aerogels, OA-MIP@Si-PC-aerogels were effectively created utilizing OA as the template molecule and MAA as the functional monomer. Due to the presence of a specific imprinted layer on the aerogel surface, the adsorption capacity of OA-MIP@Si-PC-aerogels for OA could reach 66.20 mg g-1. OA-MIP@Si-PC-aerogels could achieve a 68.86% yield of OA from the extracts of lingonberry (Vaccinium Vitis-Idaea L.). The adsorption capacity remained at 90% after five consecutive adsorption-desorption cycles. HepG2 cells were exposed to OA that was effectively enriched with OA-MIP@Si-PC-aerogels in lingonberry (Vaccinium Vitis-Idaea L.) fruit homogenates. This OA significantly inhibited the growth of HepG2 cells in vitro. It further demonstrated that OA-MIP@Si-PC-aerogels could efficiently target OA enrichment and separation with good recovery.

Development of hydroxypropyl cellulose and graphene oxide modified molecularly imprinted polymers for separation and enrichment of podophyllotoxin

A novel hydroxylpropyl cellulose (HPC) modified graphene oxide (GO)-based molecularly imprinted polymers (HPC-GO-MIP) have been developed as a solid phase extraction (SPE) material for the selective separation and extraction of podophyllotoxin. In this strategy, the cellulose with rich hydroxyl groups was introduced to form bi-functional monomers with methacrylic acid to provide more recognition sites for the improving of extraction efficiency, then GO was added as a two-dimensional substrate for MIP to improve the material morphology and surface area. The extraction performances of obtained HPC-GO-MIP material were tested, and the results prove its high efficiency and selectivity for podophyllotoxin extraction. The saturated adsorption capacity reached 23.1 μg/mg, and high enrichment efiiciency of 463.8 folds was realized under the premise of ensuring the recovery rate. The selective imprinting factor was much higher than those of kaempferol and quercetin, which were the main compounds in podophyllum fruit. Under the optimized SPE conditions, the HPC-GO-MIP based SPE-HPLC method showed the detection limit of 14.2 ng/mL for podophyllotoxin assay. When applied to podophyllum fruit samples, the material showed excellent ability of selective separation and enrichment of podophyllotoxin, and the relative standard deviations (RSD) of intra and inter batches were less than 8.1 % and 5.7 % in real samples detection. The HPC-GO-MIP SPE method broadened the application for high multiple extraction in trace analyte samples and provided a valuable solution to improve the selective separation and detection.

Molecularly imprinted electrochemical sensor based on synergistic interaction of honeycomb-like Ni-MOF decorated with AgNPs and N-GQDs for ultra-sensitive detection of olaquindox in animal-origin food

Olaquindox (OLA) in food from its illegal use possesses great harmful effects on humans, making it important to develop sensitive, inexpensive, and convenient methods for OLA detection. This study innovatively presented a molecularly imprinted electrochemical sensor based on the synergistic effects of nitrogen-doped graphene quantum dots (N-GQDs) and a nickel-based metal-organic framework functionalized with silver nanoparticles (Ag/Ni-MOF) for OLA detection. N-GQDs and Ag/Ni-MOF with unique honeycomb structures were sequentially modified on the glassy carbon electrode (GCE) surface to accelerate the electron transfer rate and increase the available region of the electrode. Molecularly imprinted polymers were further grown on the Ag/Ni-MOF/N-GQDs/GCE by electropolymerization to significantly enhance the selective recognition of OLA. The constructed sensor showed excellent performance for selective OLA determination, with a wide linear range (5-600 nmol·L^-1) and exceedingly low detection limit (2.2 nmol·L^-1). The sensor was successfully applied to detect OLA in animal-origin food with satisfactory recoveries (96.22-101.02%).

Disulfide-Bridged Dendritic Organosilicas-Based Biodegradable Molecularly Imprinted Polymers for Multiple Targeting and pH/Redox-Responsive Drug Release toward Chemical/Photodynamic Synergistic Tumor Therapy

In this study, a sialic acid (SA) and transferrin (TF) imprinted biodegradable disulfide bridging organosilicas-based drug delivery system (SS-DMONS/DOX-Ce6@MIPs) for targeted cancer therapy is constructed, for the first time. Disulfide bridged dendritic mesoporous organosilicas nanoparticles (SS-DMONs) not only enhance drug loading as the drug repository, but also provide enough specific surface area for the molecular imprinting shell to expose more degradation and imprinted sites on the surface. In addition, SS can be disturbed in a highly reducing tumor microenvironment to achieve degradation. The biodegradable imprinting film, prepared with customized 2-amino-N-(3,4-dihydroxyphenethyl)-3-mercaptopropanamide and 4-mercaptophenylboronic acid as functional monomers, endows SS-DMONs with active targeting capacity, and responsive drug release through degradation under acidic and highly reductive tumor microenvironment. SS-DMONS/DOX-Ce6@MIPs after binding of TF can target tumor cells actively through multiple interactions, including the affinity between antigen and antibody, and the specific recognition between molecularly imprinted polymers and template molecules. Under laser irradiation the loaded chlorin e6 (Ce6) that can produce toxic reactive oxygen, combined with the doxorubicin (DOX), achieves chemical/photodynamic synergistic anticancer effects. SS-DMONS/DOX-Ce6@MIPs present excellent tumor targeting and dual-responsive drug release, which provides an effective strategy for chemical/photodynamic antitumor therapy.

A molecularly imprinted photopolymer based on mesh TpPa-2 embedded with perovskite CsPbBr3 quantum dots for the sensitive solid fluorescence sensing of patulin in apple products

Here, a novel molecularly imprinted photopolymer was prepared using CsPbBr₃ quantum dots as the fluorescence source, TpPa-2 as substrate for selective solid fluorescence detection of patulin (PAT). TpPa-2 can promote efficient recognition of PAT due to its unique structure and significantly improve the fluorescence stability and sensitivity. The test results showed that the photopolymer exhibited large adsorption capacity (131.75 mg/g), fast adsorption ability (12 mins), superior reusability and high selectivity. The sensor proposed had good linearity for PAT in the range of 0.2-20 ng/mL and was applied to the analysis of PAT in apple juice and apple jam with a limit of detection as low as 0.027 ng/mL. Therefore it maybe a promising method for solid fluorescence detection of trace PAT in food analysis.

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.

Molecularly Imprinted Nanomaterials with Stimuli Responsiveness for Applications in Biomedicine

The review aims to summarize recent reports of stimuli-responsive nanomaterials based on molecularly imprinted polymers (MIPs) and discuss their applications in biomedicine. In the past few decades, MIPs have been proven to show widespread applications as new molecular recognition materials. The development of stimuli-responsive nanomaterials has successfully endowed MIPs with not only affinity properties comparable to those of natural antibodies but also the ability to respond to external stimuli (stimuli-responsive MIPs). In this review, we will discuss the synthesis of MIPs, the classification of stimuli-responsive MIP nanomaterials (MIP-NMs), their dynamic mechanisms, and their applications in biomedicine, including bioanalysis and diagnosis, biological imaging, drug delivery, disease intervention, and others. This review mainly focuses on studies of smart MIP-NMs with biomedical perspectives after 2015. We believe that this review will be helpful for the further exploration of stimuli-responsive MIP-NMs and contribute to expanding their practical applications especially in biomedicine in the near future.

Molecularly Imprinted Polymer-Coated Inorganic Nanoparticles: Fabrication and Biomedical Applications

Molecularly imprinted polymers (MIPs) continue to gain increasing attention as functional materials due to their unique characteristics such as higher stability, simple preparation, robustness, better binding capacity, and low cost. In particular, MIP-coated inorganic nanoparticles have emerged as a promising platform for various biomedical applications ranging from drug delivery to bioimaging. The integration of MIPs with inorganic nanomaterials such as silica (SiO₂), iron oxide (Fe₃O₄), gold (Au), silver (Ag), and quantum dots (QDs) combines several attributes from both components to yield highly multifunctional materials. These materials with a multicomponent hierarchical structure composed of an inorganic core and an imprinted polymer shell exhibit enhanced properties and new functionalities. This review aims to provide a general overview of key recent advances in the fabrication of MIPs-coated inorganic nanoparticles and highlight their biomedical applications, including drug delivery, biosensor, bioimaging, and bioseparation.

A highly selective molecularly imprinted electrochemical sensor with anti-interference based on GO/ZIF-67/AgNPs for the detection of p-cresol in a water environment

p-Cresol is a harmful phenolic substance that can cause serious effects on human health even at a low concentration in water. Therefore, the detection of p-cresol in a water environment is particularly important. In this paper, a novel zeolite imidazolate framework-67 (ZIF-67) material with regular morphology was prepared on the surface of graphene oxide doped with silver nanoparticles. The composite was modified on the glassy carbon electrode surface to increase the specific surface area, accelerate the electron transfer rate, enhance the current response and improve the performance of electrochemical sensors. Furthermore, a layer of p-cresol-molecularly imprinted polymer was prepared on the surface of the modified electrode by electropolymerization for the selective, rapid and sensitive detection of p-cresol, which greatly improved the specific recognition of p-cresol. Under optimal conditions, the prepared sensor had a good linear range of 1.0 × 10^-10 M to 1.0 × 10^-5 M with a detection limit as low as 5.4 × 10^-11 M, and it presented excellent reproducibility, stability and selectivity. Moreover, the sensor was successfully applied for the detection of trace p-cresol in a real water environment, providing a reliable assay for sensitive, rapid and selective detection of p-cresol in complex samples.

Biodegradable magnesium ion-doped silica-based molecularly imprinted nanoparticles for targeting tumor cells to drugs controlled release and recognition mechanism research

Herein, we designed and constructed a novel biodegradable molecularly imprinted nanoparticles (Mg-SMSNs/DOX-Ce6 @MIPs) using a new degradable functional monomer prepared by glycerol and lactide, on magnesium ion-doped stellated mesoporous silica nanoparticles (Mg-SMSNs). These nanoparticles loaded with the anticancer drug doxorubicin (DOX) and chlorin e6 (Ce6) were used to target sialic acid (SA) overexpressed on the surface of tumor cells and release drugs in response to the tumor microenvironment. The molecularly imprinted layer avoided premature drug leakage, meanwhile, the large number of ester bonds contained in the functional monomers in the layer degraded by protonation in the tumor microenvironment to expose the drugs. Mg²⁺ doping in SMSNs enhanced the degradation performance in tumor microenvironment to achieve tumor-responsive drug release. The multifunctional monomers increased the interaction with SA, enhanced the binding force, and accurately targeted recognition was obtained. The recognition mechanism of Mg-SMSNs/DOX-Ce6 @MIPs to SA and drug release were investigated by model analysis. The cytotoxicity and cellular targeting of Mg-SMSNs/DOX-Ce6 @MIPs revealed that Mg-SMSNs/DOX-Ce6 @MIPs could specifically recognize SA to target MCF-7 tumor cells without interference. Under laser irradiation, Ce6 and DOX could achieve synergistic treatment to tumor cells. Mg-SMSNs/DOX-Ce6 @MIPs present good biological abilities in terms of active targeting, pH-responsiveness, antitumor efficiency and biocompatibility.