Fluorescent Signaling of Molecularly Imprinted Nanogels Prepared via Postimprinting Modifications for Specific Protein Detection

Smart chitosan nanogel for targeted doxorubicin delivery, ensuring precise release, and minimizing side effects in Ehrlich ascites carcinoma-bearing mice

In recent decades, bio-polymeric nanogels have become a forefront in medical research as innovative in-vivo drug carriers. This study introduces a pH-sensitive chitosan nanoparticles/P(N-Isopropylacrylamide-co-Acrylic acid) nanogel (CSNPs/P(NIPAm-co-AAc)), making significant advancements. The nanogel effectively encapsulated doxorubicin hydrochloride (Dx. HCl), a model drug, within its compartments through electrostatic binding. Comparing nano chitosan (CSNPs) before and after integrating copolymerized P(NIPAm-co-AAc), highlighting an improved and adaptable nanogel structure with responsive behaviors. The intraperitoneal delivery of Dx-loaded nanogel (Dx@N.gel) to Ehrlich ascites carcinoma (Eh)-bearing mice at doses equivalent to 1.5 and 3 mg/kg of Dx per day for 14 days exhibited superiority over the administration of free Dx. Dx@N.gel demonstrated heightened anticancer activity, significantly improving mean survival rates in Eh mice. The nanogel's multifaceted defense mechanism mitigated oxidative stress, inhibited lipid peroxidation, and curbed nitric oxide formation induced by free Dx. It effectively countered hepatic DNA deterioration, normalized elevated liver and cardiac enzyme levels, and ameliorated renal complications. This pH-responsive CSNPs/P(NIPAm-co-AAc) nanogel loaded with Dx represents a paradigm shift in antitumor drug delivery. Its efficacy and ability to minimize side effects, contrasting sharply with those of free Dx, offer a promising future where potent cancer therapies seamlessly align with patient well-being.

Post-imprinting modification of molecularly imprinted polymer for proteins detection: A review

Inspired by protein post-translational modification (PTM), post-imprinting modification (PIM) has been proposed and developed to prepare novel molecularly imprinted polymers (MIPs), which are similar to functionalized biosynthetic proteins. The PIM involves site-directed modifications in the imprinted cavity of the MIP, such as introducing high-affinity binding sites and introducing fluorescent signal molecules. This modification makes the MIP further functionalized and improves the shortcomings of general molecular imprinting, such as single function, low selectivity, low sensitivity, and inability to fully restore the complex function of natural antibodies. This paper describes the characteristics of PIM strategies, reviews the latest research progress in the recognition and detection of protein biomarkers such as lysozyme, prostate-specific antigen, alpha-fetoprotein, human serum albumin, and peptides, and further discusses the importance, main challenges, and development prospects of PIM. The PIM technology has the potential to develop a new generation of biomimetic recognition materials beyond natural antibodies. It can be used in bioanalysis and other multitudinous fields for its unique features in molecule recognition.

A rapid abiotic/biotic hybrid sandwich detection for trace pork adulteration in halal meat extract

In this study, we prepared molecularly imprinted polymer nanogels with good affinity for the Fc domain of immunoglobulin G (IgG) using 4-(2-methacrylamidoethylaminomethyl) phenylboronic acid as a modifiable functional monomer for post-imprinting in-cavity modification of a fluorescent dye (F-Fc-MIP-NGs). A novel nanogel-based biotic/abiotic hybrid sandwich detection system for porcine serum albumin (PSA) was developed using F-Fc-MIP-NGs as an alternative to a secondary antibody for fluorescence detection and another molecularly imprinted polymer nanogel capable of recognizing PSA (PSA-MIP-NGs) as a capturing artificial antibody, along with a natural antibody toward PSA (Anti-PSA) that was used as a primary antibody. After incubation of PSA and Anti-PSA with F-Fc-MIP-NGs, the PSA/Anti-PSA/F-Fc-MIP-NGs complex was captured by immobilized PSA-MIP-NGs for fluorescence measurements. The analysis time was less than 30 min for detecting pork adulteration of 0.01 wt% in halal beef and lamb meats. The detection limit was comparable to that of frequently used immunoassays. Therefore, we believe that this method is a promising, sensitive, and rapid detection method for impurities in real samples and could be a simple, inexpensive, and rapid alternative to conventional methods that have cumbersome procedures of 4 hours or more.

Molecularly Imprinted Polymer-Based Luminescent Chemosensors

Molecularly imprinted polymer (MIP)-based luminescent chemosensors combine the advantages of the highly specific molecular recognition of the imprinting sites and the high sensitivity with the luminescence detection. These advantages have drawn great attention during the past two decades. Luminescent molecularly imprinted polymers (luminescent MIPs) towards different targeted analytes are constructed with different strategies, such as the incorporation of luminescent functional monomers, physical entrapment, covalent attachment of luminescent signaling elements on the MIPs, and surface-imprinting polymerization on the luminescent nanomaterials. In this review, we will discuss the design strategies and sensing approaches of luminescent MIP-based chemosensors, as well as their selected applications in biosensing, bioimaging, food safety, and clinical diagnosis. The limitations and prospects for the future development of MIP-based luminescent chemosensors will also be discussed.

Multicolor Polystyrene Nanosensors for the Monitoring of Acidic, Neutral, and Basic pH Values and Cellular Uptake Studies

A first tricolor fluorescent pH nanosensor is presented, which was rationally designed from biocompatible carboxylated polystyrene nanoparticles and two analyte-responsive molecular fluorophores. Its fabrication involved particle staining with a blue-red-emissive dyad, consisting of a rhodamine moiety responsive to acidic pH values and a pH-inert quinoline fluorophore, followed by the covalent attachment of a fluorescein dye to the particle surface that signals neutral and basic pH values with a green fluorescence. These sensor particles change their fluorescence from blue to red and green, depending on the pH and excitation wavelength, and enable ratiometric pH measurements in the pH range of 3.0-9.0. The localization of the different sensor dyes in the particle core and at the particle surface was confirmed with fluorescence microscopy utilizing analogously prepared polystyrene microparticles. To show the application potential of these polystyrene-based multicolor sensor particles, fluorescence microscopy studies with a human A549 cell line were performed, which revealed the cellular uptake of the pH nanosensor and the differently colored emissions in different cell organelles, that is, compartments of the endosomal-lysosomal pathway. Our results demonstrate the underexplored potential of biocompatible polystyrene particles for multicolor and multianalyte sensing and bioimaging utilizing hydrophobic and/or hydrophilic stimuli-responsive luminophores.

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.