Fabrication and characterization of pH ‐responsive poly (methacrylic acid)‐based molecularly imprinted polymers nanosphere for controlled release of amitriptyline hydrochloride

Precipitation Polymerization-Based Molecularly Imprinted Polymers: A Novel Approach for Transdermal Curcumin Delivery

This research describes the synthesis and characterization of a molecularly imprinted polymer (MIP) as a candidate for the transdermal delivery of curcumin. The MIP was synthesized through precipitation polymerization using methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linking agent. MIP characterization studies were conducted using SEM-EDX and FTIR spectroscopy to determine the morphology and interaction between curcumin and polymers. The MIP obtained through precipitation polymerization was in the form of a fine powder with a surface morphology resembling a collection of small granules with a uniform shape. The adsorption capacity of the MIP follows the Langmuir adsorption isotherm model, with a maximum capacity of 4.239 mg/g, which is greater than that of the NIP (3.219 mg/g), resulting in an imprinting efficiency of 1.317. The percentage of curcumin released from the MIP after 8 h was 41.26%, which is lower than that from the NIP, at 51.50%. The drug release kinetics study follows the Higuchi model, indicating drug diffusion from the polymer matrix. Imprinting on the MIP can modify drug diffusion from the polymer matrix, resulting in a reduced release rate in the MIP. Therefore, the MIP can be considered a candidate for the controlled transdermal delivery of curcumin.

Molecular imprinting technology for electrochemical sensing of kasugamycin in food products based on Cu2+/Cu+ stripping current

An electrochemical sensing approach was developed for the detection of the agricultural antibiotic drug kasugamycin. The method involves the construction of an electrochemical sensor comprising molecularly imprinted polymers (MIPs) embedded within a carbon paste (CP) matrix. The MIPs are designed to have imprinted sites that match the size and geometry of the Cu(II)-kasugamycin coordinated complex. Upon removal of kasugamycin, cavities suitable for the drug's entrance are formed within the MIPs. The presence of Cu(II) facilitates the detection of the drug by generating a redox signal of Cu(II)-Cu(I), which can be easily detected using differential pulse voltammetry (DPV). The signal response of Cu(II)-Cu(I) increases in the presence of the drug, promoting the accumulation of Cu(II) ions within the imprinted cavities. Under optimized conditions, the anodic peak (Ipa) signal of Cu(II)-Cu(I) exhibits an increase proportional to the concentration of kasugamycin within the range of 0.15-140 μM. The detection limit (LOD, S/N = 3) achieved is 0.046 μM. The proposed sensor demonstrates several characteristic features including good stability, reliable performance, a low detection limit, and excellent selectivity. The Cu(II)-MIP@CP sensor proved effective in detecting kasugamycin within complex samples like meat, milk, and cucumber, yielding recovery% ranging from 96.0 to 103.8%. Additionally, the relative standard deviation % (RSD%) fell within the range of 2.2% to 4.0%, indicating good precision and reliability.

Boosting Electrochemical Sensing Performances Using Molecularly Imprinted Nanoparticles

Nanoparticles of molecularly imprinted polymers (nanoMIPs) combine the excellent recognition ability of imprinted polymers with specific properties related to the nanosize, such as a high surface-to-volume ratio, resulting in highly performing recognition elements with surface-exposed binding sites that promote the interaction with the target and, in turn, binding kinetics. Different synthetic strategies are currently available to produce nanoMIPs, with the possibility to select specific conditions in relation to the nature of monomers/templates and, importantly, to tune the nanoparticle size. The excellent sensing properties, combined with the size, tunability, and flexibility of synthetic protocols applicable to different targets, have enabled the widespread use of nanoMIPs in several applications, including sensors, imaging, and drug delivery. The present review summarizes nanoMIPs applications in sensors, specifically focusing on electrochemical detection, for which nanoMIPs have been mostly applied. After a general survey of the most widely adopted nanoMIP synthetic approaches, the integration of imprinted nanoparticles with electrochemical transducers will be discussed, representing a key step for enabling a reliable and stable sensor response. The mechanisms for electrochemical signal generation will also be compared, followed by an illustration of nanoMIP-based electrochemical sensor employment in several application fields. The high potentialities of nanoMIP-based electrochemical sensors are presented, and possible reasons that still limit their commercialization and issues to be resolved for coupling electrochemical sensing and nanoMIPs in an increasingly widespread daily-use technology are discussed.

A molecularly imprinted electrochemical sensor for specific and ultrasensitive determination of an aminoglycoside drug: the role of copper ions in the determination

Herein, a molecularly imprinted polymer (MIP) was fabricated for specific sensing of an aminoglycoside e.g. kanamycin (KANA). Carbon paste modified with a MIP specific to Cu²⁺-KANA was first introduced. Copper (Cu²⁺) as a metal ion was used as a signal tracer and an amplifier, producing a current response measured by differential pulse voltammetry (DPV). Introducing the aminoglycoside drug into the solution containing Cu²⁺ did not affect the current response of the NIP/CPE. Under the optimum conditions, the as-fabricated sensor exhibited an increase in the current response in the range of 0.55-550 nM with a good limit of detection (LOD, S/N = 3) of 161 pM. The sensor exhibited many advantages including high sensitivity and selectivity, good stability and reproducibility, and cost-effectiveness. Moreover, it was successfully applied for the determination of KANA in milk and honey samples with RSD % not more than 3.3%, suggesting the reliability of the as-designed sensor.

Molecularly imprinted ormosil as a sorbent for targeted dispersive solid phase micro extraction of pyriproxyfen from strawberry samples

Novel molecularly imprinted organically modified silica was prepared by reacting acrylamide and 3-(tri-methoxysilyl) propyl methacrylate followed by condensation and hydrolysis with tetraethyl ortho-silicate for the determination of pyriproxyfen. The sorbent proved to be highly selective for the template molecule, pyriproxyfen. The characterization of sorbent was carried out using SEM, BET and TGA. The prominent peaks in FTIR at 3700 cm^-1 and 1071 cm^-1 confirmed the stretching of amide group's N-H and Si-O-Si bond linkage of MI_Ormosil. The pseudo-first-order model (R² 0.99) described the adsorption kinetics of the MI_Ormosil, whereas among adsorption isotherms, Freundlich model showed the best fit (R² 0.99). The molecularly imprinted silica was applied for the determination of target analytes from strawberries sample using dispersive solid-phase micro extraction (DSPME) followed by high-performance liquid chromatography (HPLC). The LOD (4.93 x10^-5 μg mL^-1) and LOQ (1.49 x10^-4 μg m-¹) values were calculated by signal to noise ratio through HPLC. Results show that the maximum binding capacity and percentage recovery values of MI_Ormosil were 13 mg g^-1 (n = 5) and 97.3% respectively.

Precipitation Polymerization: A Powerful Tool for Preparation of Uniform Polymer Particles

Precipitation polymerization (PP) is a powerful tool to prepare various types of uniform polymer particles owing to its outstanding advantages of easy operation and the absence of any surfactant. Several PP approaches have been developed up to now, including traditional thermo-induced precipitation polymerization (TRPP), distillation precipitation polymerization (DPP), reflux precipitation polymerization (RPP), photoinduced precipitation polymerization (PPP), solvothermal precipitation polymerization (SPP), controlled/‘‘living’’ radical precipitation polymerization (CRPP) and self-stabilized precipitation polymerization (2SPP). In this review, a general introduction to the categories, mechanisms, and applications of precipitation polymerization and the recent developments are presented, proving that PP has great potential to become one of the most attractive polymerization techniques in materials science and bio-medical areas.

Customizable molecular recognition: advancements in design, synthesis, and application of molecularly imprinted polymers

Molecularly imprinted polymers (MIPs) are unlocking the door to synthetic materials that are capable of molecular recognition.