Recognition Properties and Competitive Assays of a Dual Dopamine/Serotonin Selective Molecularly Imprinted Polymer

A molecularly imprinted polymer (MIP) with dual dopamine/serotonin-like binding sites (DS-MIP) was synthesized for use as a receptor model of study the drug-interaction of biological mixed receptors at a molecular level. The polymer material was produced using methacrylic acid (MAA) and acrylamide (ACM) as functional monomers, N,N′-methylene bisacrylamide (MBAA) as cross-linker, methanol/water mixture (4:1, v/v) as porogen and a mixture of dopamine (D) and serotonin (S) as templates. The prepared DS-MIP exhibited the greatest rebinding of the template(s) in aqueous methanol solution with decreased recognition in acetonitrile, water and methanol solvent. The binding affinity and binding capacity of DS-MIP with S were found to be higher than those of DS-MIP with D. The selectivity profiles of DS-MIP suggest that the D binding site of DS-MIP has sufficient integrity to discriminate between species of non-optimal functional group orientation, whilst the S binding site of DS-MIP is less selective toward species having structural features and functional group orientations different from S. The ligand binding activities of a series of ergot derivatives (ergocryptine, ergocornine, ergocristine, ergonovine, agroclavine, pergolide and terguride) have been studied with the DS-MIP using a competitive ligand binding assay protocol. The binding affinities of DS-MIP were demonstrated in the micro- or submicro-molar range for a series of ergot derivatives, whereas the binding affinities were considerably greater to natural receptors derived from the rat hypothalamus. The DS-MIP afforded the same pattern of differentiation as the natural receptors, i.e. affinity for the clavines > lysergic acid derivatives > ergopeptines. The results suggest that the discrimination for the ergot derivatives by the dopamine and serotonin sites of DS-MIP is due to the structural features and functional orientation of the phenylethylamine and indolylethylamine entities at the binding sites, and the fidelity of the dopamine and serotonin imprinted cavities

Synergistic Effect of Pericarp of Mangosteen and Propolis from Stingless Bee Extracts on Nitric Oxide Scavenging Activity

The aim of this research is to study the synergistic effect on the nitric oxide scavenging activity of mangosteen pericarp and the stingless bee (Tetragonula laviceps) propolis extracts and their phytochemical constituents. The propolis and mangosteen pericarp were extracted by reflux method with ethanol. TPC and TFC of propolis extract were 123.73±2.80 mg GAE/g extract and 70.65±11.21 mg QE/g extract, respectively, and mangosteen pericarp extract was 387.93±15.10 mg GAE/g extract and 87.00±5.06 mg QE/g extract, respectively. The ESI-LC-MS data displayed that both extracts have a variety of phytochemical constituents, such as xanthones, flavonoids, and miscellaneous. The synergistic effect of Nitric oxide scavenging activities of propolis and mangosteen pericarp extracts showed higher activity than individual extracts with various concentrations. Thus, the synergistic effect of propolis and mangosteen pericarp extracts may be an alternative source of inflammatory drug development in the future

Enhancing protein trapping efficiency of graphene oxide-polybutylene succinate nanofiber membrane via molecular imprinting

Abstract Filtration of biological liquids has been widely employed in biological, medical, and environmental investigations due to its convenience; many could be performed without energy and on-site, particularly protein separation. However, most available membranes are universal protein absorption or sub-fractionation due to molecule sizes or properties. SPMA, or syringe-push membrane absorption, is a quick and easy way to prepare biofluids for protein evaluation. The idea of initiating SPMA was to filter proteins from human urine for subsequent proteomic analysis. In our previous study, we developed nanofiber membranes made from polybutylene succinate (PBS) composed of graphene oxide (GO) for SPMA. In this study, we combined molecular imprinting with our developed PBS fiber membranes mixed with graphene oxide to improve protein capture selectivity in a lock-and-key fashion and thereby increase the efficacy of protein capture. As a model, we selected albumin from human serum (ABH), a clinically significant urine biomarker, for proteomic application. The nanofibrous membrane was generated utilizing the electrospinning technique with PBS/GO composite. The PBS/GO solution mixed with ABH was injected from a syringe and transformed into nanofibers by an electric voltage, which led the fibers to a rotating collector spinning for fiber collection. The imprinting process was carried out by removing the albumin protein template from the membrane through immersion of the membrane in a 60% acetonitrile solution for 4 h to generate a molecular imprint on the membrane. Protein trapping ability, high surface area, the potential for producing affinity with proteins, and molecular-level memory were all evaluated using the fabricated membrane morphology, protein binding capacity, and quantitative protein measurement. This study revealed that GO is a controlling factor, increasing electrical conductivity and reducing fiber sizes and membrane pore areas in PBS-GO-composites. On the other hand, the molecular imprinting did not influence membrane shape, nanofiber size, or density. Human albumin imprinted membrane could increase the PBS-GO membrane’s ABH binding capacity from 50 to 83%. It can be indicated that applying the imprinting technique in combination with the graphene oxide composite technique resulted in enhanced ABH binding capabilities than using either technique individually in membrane fabrication. The suitable protein elution solution is at 60% acetonitrile with an immersion time of 4 h. Our approach has resulted in the possibility of improving filter membranes for protein enrichment and storage in a variety of biological fluids

3D-printed scaffold of dopamine methacrylate oligomer grafted on PEGDMA incorporated with collagen hydrolysate for engineering cartilage tissue

This study demonstrated the synthesis and characterization of dopamine methacrylate (DMA), oligomers of dopamine methacrylate (ODMA), and their integration with polyethylene glycol dimethacrylate (PEGDMA) to enhance 3D-printing scaffold fabrication for tissue engineering, using digital light processing (DLP) technology. The results confirm the successful synthesis of DMA, as evidenced by nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR) analysis and its subsequent conversion to ODMA. The obtained ODMA was then combined with PEGDMA (1.25–10% w/v ODMA) to optimize scaffold printability. The morphological characteristics of the ODMA/PEGDMA scaffolds were assessed via scanning electron microscopy (SEM). Furthermore, using FTIR and differential scanning calorimetry (DSC), the chemical stability and biological compatibility of collagen hydrolysate (CH) derived from tuna tendon were studied and compared after sterilization. An in vitro fibroblast viability test was conducted using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay to assess the biocompatibility of CH with cells. Sterilization did not adversely affect the chemical composition of CH, maintaining its compatibility with fibroblast cells. Subsequently, ODMA/PEGDMA/CH composite scaffolds were fabricated using a DLP 3D printer, and their efficacy in supporting chondrocyte viability and proliferation were examined at 24, 48, and 72 h using PrestoBlue® assay. Mixing ODMA with PEGDMA significantly enhanced the printability of the scaffolds. Our tri-component 3D-printed scaffolds significantly enhanced human cartilage stem/progenitor cell (CSPC) viability and proliferation compared to a 24-well culture plate. These scaffolds excel in both mechanical properties, crucial for bearing physiological loads, and biological properties that promote cell growth and proliferation. This dual enhancement underscores their superior performance and positions them as frontrunners in the development of advanced solutions for cartilage engineering, potentially revolutionizing medical treatments