State of the art in development of molecularly imprinted biosensors

Decoding the "Fingerprint" of Implant Materials: Insights into the Foreign Body Reaction

Foreign body reaction (FBR) is a prevalent yet often overlooked pathological phenomenon, particularly within the field of biomedical implantation. The presence of FBR poses a heavy burden on both the medical and socioeconomic systems. This review seeks to elucidate the protein "fingerprint" of implant materials, which is generated by the physiochemical properties of the implant materials themselves. In this review, the activity of macrophages, the formation of foreign body giant cells (FBGCs), and the development of fibrosis capsules in the context of FBR are introduced. Additionally, the relationship between various implant materials and FBR is elucidated in detail, as is an overview of the existing approaches and technologies employed to alleviate FBR. Finally, the significance of implant components (metallic materials and non-metallic materials), surface CHEMISTRY (charge and wettability), and physical characteristics (topography, roughness, and stiffness) in establishing the protein "fingerprint" of implant materials is also well documented. In conclusion, this review aims to emphasize the importance of FBR on implant materials and provides the current perspectives and approaches in developing implant materials with anti-FBR properties.

Tailor-made molecular imprints for biological event intervention

Molecular imprints, which are crosslinked architectures containing specific molecular recognition cavities for targeting compounds, have recently transitioned from in vitro diagnosis to in vivo treatment. In current application scenarios, it has become an important topic to create new biomolecular recognition pathways through molecular imprinting, thereby inhibiting the pathogenesis and regulating the development of diseases. This review starts with a pathological analysis, mainly focusing on the corresponding artificial enzymes, enzyme inhibitors and antibody mimics with enhanced functions that are created by molecular imprinting strategies. Recent advances are highlighted in the use of molecular imprints as tailor-made nanomedicines for the prevention of three major diseases: metabolic syndrome, cancer, and bacterial/viral infections.

An innovative and universal dual-signal ratiometric spectro-electrochemical imprinted sensor design for sandwich type detection of anticancer-drug, gemcitabine, in serum samples; cross validation via computational modeling

An innovative and universal imprinted sensor design for sandwich type detection of gemcitabine (GMT) in human serum samples is described. GMT is widely used in the treatment of different tumors, such as lung, ovarian, pancreatic, and breast cancer. The serum albumin-drug interaction was translated to design a multifunctional, ratiometric and dual mode silver nanoparticle based probe (BSA-Ag nanoprobe), as a read out system. Subsequently, polypyrrol imprinted drug receptor sites was engineered to selectively capture the GMT on the transducer surface. The GMT was sandwiched between imprinted receptor surface and BSA-Ag nanoprobe to generate the spectro-electrochemical signals. The formation of nanoprobe was confirmed through various characterization techniques, including X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, micro-Raman spectroscopy, Dynamic light scattering (DLS), and UV-Visible (UV-Vis) analysis, while each step of sensor fabrication was characterized via field emission scanning electron microscope (FE-SEM), Static water Contact angle measurements, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). Different variable parameters were optimized to improve the analytical performance of the sensor design. Under optimal conditions, spectro-electrochemical sensor permitted linear ranges between 1 and 200 μmol L-1 and 0.5-200 μmol L-1, with limits of detection (LOD) of 0.4 μmol L-1 and 0.15 μmol L-1 respectively. Furthermore, the designed sensor successfully differentiated the serum samples of lung cancer patients and healthy volunteers. The obtained results were validated with standard Liquid chromatography-mass spectrometry (LC/MS) analysis of the patients and healthy volunteer's serum samples. Lastly, density functional theory (DFT) and molecular docking calculations revealed the enhanced GMT binding capability of molecularly imprinted polypyrrole and molecular level interaction between the GMT and BSA, to validate the sandwich sensor design.

Recent Advances in Bioelectronics for Localized Drug Delivery

The last decade has witnessed remarkable advancements in bioelectronics, ushering in a new era of wearable and implantable devices for drug delivery. By utilizing miniaturized system design and/or flexible materials, bioelectronics illustrates ideal integration with target organs and tissues, making them ideal platforms for localized drug delivery. Furthermore, the development of electrically assisted drug delivery systems has enhanced the efficiency and safety of therapeutic administration, particularly for the macromolecules that encounter additional challenges in penetrating biological barriers. In this review, a concise overview of recent progress in bioelectronic devices for in vivo localized drug delivery, with highlights on the latest trends in device design, working principles, and their corresponding functionalities, is provided. The reported systems based on their targeted delivery locations as wearable systems, ingestible systems, and implantable systems are categorized. Each category is introduced in detail by highlighting the special requirements for devices and the corresponding solutions. The remaining challenges in this field and future directions are also discussed.

Molecularly Imprinted Electrochemical Sensors Based on Ti3C2Tx-MXene and Graphene Composite Modifications for Ultrasensitive Cortisol Detection

The increasing pressure and unhealthy lifestyle are gradually eroding the physical and mental health of modern people. As a key hormone responsible for maintaining the normal functioning of human systems, cortisol plays a vital role in regulating physiological activities. Moreover, cortisol can serve as a marker for monitoring psychological stress. The development of cortisol detection sensors carries immense potential, as they not only facilitate timely adjustments and treatments by detecting abnormal physiological indicators but also provide comprehensive data for conducting research on the correlation between cortisol and several potential diseases. Here, we report a molecularly imprinted polymer (MIP) electrochemical biosensor that utilizes a porous composite (MXG) modified electrode. MXG composite is prepared by combining Ti3C2Tx-MXene sheets and graphene (Gr). MXG composite material with high conductive properties and large electroactive surface area promotes the charge transfer capability of the electrode surface, expands the effective surface area of the sensor, and increases the content of cortisol-imprinted cavities on the electrode, thereby improving the sensing ability of the sensor. By optimizing the preparation process, the prepared sensor has an ultralow lower limit of detection of 0.4 fM, a wide detection range of 1 fM-10 μM, and good specificity for steroid hormones and interfering substances with similar cortisol structure. The ability of the sensor to detect cortisol in saliva was also confirmed experimentally. This highly sensitive and selective cortisol sensor is expected to be widely used in the fields of physiological and psychological care.

Novel electrochemical sensing platform basing on di-functional stimuli-responsive imprinted polymers for simultaneous extraction and determination of metronidazole

A novel magnetic-controlled electrochemical sensor has been fabricated by combined photo-responsive surface molecular imprinted polymers (P-SMIPs) and electrochemical sensor. In particular, the P-SMIPs were obtained by living radical polymerization of photo-responsive functional monomer onto the magnetic Fe₃O₄ modified multi-walled carbon nanotubes nanocomposites. The magnetic glassy carbon electrode was introduced to make the anchoring and removal of P-SMIPs onto the magnetic-controlled glassy carbon electrode easy to manipulate. Driven by UV/vis light, the platform performs releasing and absorption of metronidazole basing on conformational variations of the photo-responsive monomer at the receptor sites part in the P-SMIPs. This process can be tested by the photo-responsive variations of metronidazole electrochemical signal. As the consequence, extracting of P-SMIPs sensor can be conveniently triggered by the controllable UV light intervention measure, leading to effectively improve in both analytes mass transfer rate to the receiving media and extraction efficiency. The experimental result indicated that the excellent recoveries of metronidazole were varied between 77.9% and 89.9% with RSDs ≤4.87% in the biological samples. Therefore, the P-SMIPs sensor shows satisfactory potential in reusable extractions that can be recycled several times with no significant loss of activity, and this utilization strategy can be extended to other analytes, achieving manifold applications of pharmaceutical and environmental.

Functional microneedles for wearable electronics

With an ideal comfort level, sensitivity, reliability, and user-friendliness, wearable sensors are making great contributions to daily health care, nursing care, early disease discovery, and body monitoring. Some wearable sensors are imparted with hierarchical and uneven microstructures, such as microneedle structures, which not only facilitate the access to multiple bio-analysts in the human body but also improve the abilities to detect feeble body signals. In this paper, we present the promising applications and latest progress of functional microneedles in wearable sensors. We begin by discussing the roles of microneedles as sensing units, including how the signals are captured, converted, and transmitted. We also introduce the microneedle-like structures as power units, which depend on triboelectric or piezoelectric effects, etc. Finally, we summarize the cutting-edge applications of microneedle-based wearable sensors in biophysical signal monitoring and biochemical analyte detection, and provide critical thinking on their future perspectives.

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.

A molecularly imprinted antibiotic receptor on magnetic nanotubes for the detection and removal of environmental oxytetracycline

The detection and elimination of antibiotic contaminants, such as oxytetracycline (OTC), a broad-spectrum tetracycline antibiotic, would be of help in efficient environmental monitoring, agriculture and food safety tests. Nevertheless, currently available methodologies, which mostly rely on the chromatographic separation of OTC, suffer from low sensitivity and complicated processes. Thus, we report here on the design and synthesis of a fluorescent sensor based on molecularly imprinted magnetic halloysite nanotubes (referred to as MHNTs@FMIPs) for the effective detection and purification of OTC in actual environmental samples. The fluorescence of the MHNTs@FMIPs was quenched obviously upon loading with OTC, covering a linear concentration range of 10-300 nM with a limit of detection (LOD) as low as 8.1 nM. The imprinting factor is 4.47, indicating an excellent specificity. Furthermore, the MHNTs@FMIPs can be applied to the quantitative detection of OTC (5 cycles of 300 nM) in aquaculture wastewater and Yangtze River water, demonstrating their immense application potential.