Surface imprinting by using bi-functional monomers on spherical template magnetite for selective detection of levodopa in biological fluids

The present work introduces an innovative biosensing platform for greatly sensitive determination of levodopa medicine. Initially, spherical magnetic (SM) nanoparticles were prepared by hydrothermal fabrication approach and used as a pattern to make spherical magnetic molecular imprinted polymer (SMMIP). Afterward, levodopa-molecularly imprinted layer was grown on the surface of the spherical magnetic pattern by electropolymerization with dopamine and resorcinol as bi-functional monomers and levodopa as a template molecule, which enhanced the specific recognition of the sensing platform to levodopa. The presence of SM nanoparticles could not only accelerate the mass transfer, the electron transport rate, and improve specific surface area of the electrode but also facilitate the recognition of the polymer, in this way increasing the current response and improving the performance of the biosensor. The superior sensing efficiency of the presented biosensor was confirmed based on the low limit of detection of 10 nmol L^-1 which represented two linear ranges from 0.5 to 200 μmol L^-1 and 200-1000 μmol L^-1 for levodopa. More importantly, the practicability of the biosensor was proved by detecting levodopa in tablet, blood serum and plasma, implying that the sensing platform was suitable for monitoring levodopa in actual biological fluid and medicine.

Facile imprinted polymer for label-free highly selective potentiometric sensing of proteins: case of recombinant human erythropoietin

In the current study, a molecularly imprinted polymer (MIP)-based potentiometric sensor was fabricated for a label-free determination of recombinant human erythropoietin (rhEPO). The MIP sensor was operated under zero current conditions using tetra-butyl ammonium bromide as a marker ion. A highly ordered rhEPO surface imprinted layer was prepared using 3-aminopropyl triethoxysilane and tetraethoxysilane as a monomer and cross-linker, respectively, under mild reaction conditions. A two-fold increase in the signal output was obtained by polymeric surface minimization (0.5 mm) that allowed more pronounced molecular recognition (imprinting factor = 20.1). The proportion of cross-reactivity was examined using different interfering biomolecules. Results confirmed sensor specificity for both structurally related and unrelated proteins. An ~40% decrease in the response was obtained for rhEPO-β compared to rhEPO-α. The imprinted polymeric surface was evaluated using scanning electron microscopy and Fourier transform infrared spectroscopy. Under the optimal measurement conditions, a linear range of 10.00-1000.00 ng mL^-1 (10^-10 - 10^-8 M) was obtained. The sensor was employed for the determination of rhEPO in different biopharmaceutical formulations. Results were validated against standard immunoassay. Spiked human serum samples were analyzed and the assay was validated. The presence of non-specific proteins did not significantly affect (~8%) the results of our assay. A concentration-dependent linear response was produced in an identical range with detection limit as low as 6.50 ng mL^-1 (2.14 × 10^-10 M). The facile fabricated MIP sensor offers a cost-effective, portable, and easy to use alternative for biosimilarity assessment and clinical application.

Preparation of surface molecularly imprinted polymer and its application for the selective extraction of teicoplanin from water

In this study, a new surface molecularly imprinted polymer (SMIP) of teicoplanin (TEC) was prepared in an aqueous solution using amino-modified silica gel as a carrier. The molar ratio of the template molecule, functional monomer and cross-linker in the optimized synthesis system was 1 : 15 : 40. The structure and morphology of SMIP were characterized by Fourier-transform infrared spectra and scanning electron microscopy, respectively. It was shown that the silica gel modified with different active groups; the type and structure of functional monomers have a great influence on the specificity of SMIP. The SMIPs synthesized from a series of methacrylic acid and its hydroxylalkyl esters as functional monomers have good specificity for TEC. The results of static adsorption experiments showed that the adsorption capacity of SMIP was 6.5 times that of non-molecularly imprinted polymer, which were 152.6 mg g⁻¹ and 23.6 mg g⁻¹, respectively, indicating that SMIP had a larger affinity for TEC. Finally, the SMIP was successfully used as a dispersive solid-phase extraction adsorption material to selectively extract and enrich TEC from the water sample. The limit of detection of the proposed liquid chromatographic method for TEC was 5 μg L⁻¹.

A novel surface molecularly imprinted polymer for specific absorbing teicoplanin in environmental water.

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

Magnetic nanoparticles coated with protein-specific molecularly imprinted polymers (MIPs) are receiving increasing attention thanks to their binding abilities, robustness, and easy synthesis compared to their natural analogues also able to target proteins, such as antibodies or aptamers. Acting as tailor-made recognition systems, protein-specific MIPs can be used in many in vivo nanomedicine applications, such as targeted drug delivery, biosensing, and tissue engineering. Nonetheless, studies on their biocompatibility and long-term fate in biological environments are almost nonexistent, although these questions have to be addressed before considering clinical applications. To alleviate this lack of knowledge, we propose here to monitor the effect of a protein-specific MIP coating on the toxicity and biodegradation of magnetic iron oxide nanoparticles, both in a minimal aqueous degradation medium and in a model of cartilage tissue formed by differentiated human mesenchymal stem cells. Degradation of iron oxide nanoparticles with or without the polymer coating was monitored for a month by following their magnetic properties using vibrating sample magnetometry and their morphology by transmission electron microscopy. We showed that the MIP coating of magnetic iron oxide nanoparticles does not affect their biocompatibility or internalization inside cells. Remarkably, the imprinted polymer coating does not hinder the magnetic particle degradation but seems to slow it down, although this effect is more visible when degradation occurs in the buffer medium than in cells. Hence, the results presented in this paper are really encouraging and open up the way to future applications of MIP-coated nanoparticles into the clinic.

Magnetic protein imprinted polymers: a review

Protein imprinted polymers have received a lot of interest in the past few years because of their applications as tailor-made receptors for biomacromolecules. Generally, the preparation of these polymers requires numerous and time-consuming steps. But their coupling with magnetic nanoparticles simplifies and speeds up the synthesis of these materials. Some recent papers describe the use of protein imprinted polymer (PIP) coupled to magnetic iron oxide nanoparticles (MION) for the design of MION@PIP biosensors. With such systems, a target protein can be specifically and selectively captured from complex media due to exceptional chemical properties of the polymer. Despite such performances, only a limited number of studies address these hybrid nanosystems. This review focuses on the chemistry and preparation of MION@PIP nanocomposites as well as on the metrics used to characterize their performances.

Hydrogels for Biomedical Applications: Cellulose, Chitosan, and Protein/Peptide Derivatives

Hydrogels based on polysaccharide and protein natural polymers are of great interest in biomedical applications and more specifically for tissue regeneration and drug delivery. Cellulose, chitosan (a chitin derivative), and collagen are probably the most important components since they are the most abundant natural polymers on earth (cellulose and chitin) and in the human body (collagen). Peptides also merit attention because their self-assembling properties mimic the proteins that are present in the extracellular matrix. The present review is mainly focused on explaining the recent advances on hydrogels derived from the indicated polymers or their combinations. Attention has also been paid to the development of hydrogels for innovative biomedical uses. Therefore, smart materials displaying stimuli responsiveness and having shape memory properties are considered. The use of micro- and nanogels for drug delivery applications is also discussed, as well as the high potential of protein-based hydrogels in the production of bioactive matrices with recognition ability (molecular imprinting). Finally, mention is also given to the development of 3D bioprinting technologies.

Molecular Imprinting of Macromolecules for Sensor Applications

Molecular recognition has an important role in numerous living systems. One of the most important molecular recognition methods is molecular imprinting, which allows host compounds to recognize and detect several molecules rapidly, sensitively and selectively. Compared to natural systems, molecular imprinting methods have some important features such as low cost, robustness, high recognition ability and long term durability which allows molecularly imprinted polymers to be used in various biotechnological applications, such as chromatography, drug delivery, nanotechnology, and sensor technology. Sensors are important tools because of their ability to figure out a potentially large number of analytical difficulties in various areas with different macromolecular targets. Proteins, enzymes, nucleic acids, antibodies, viruses and cells are defined as macromolecules that have wide range of functions are very important. Thus, macromolecules detection has gained great attention in concerning the improvement in most of the studies. The applications of macromolecule imprinted sensors will have a spacious exploration according to the low cost, high specificity and stability. In this review, macromolecules for molecularly imprinted sensor applications are structured according to the definition of molecular imprinting methods, developments in macromolecular imprinting methods, macromolecular imprinted sensors, and conclusions and future perspectives. This chapter follows the latter strategies and focuses on the applications of macromolecular imprinted sensors. This allows discussion on how sensor strategy is brought to solve the macromolecules imprinting.