Research progress of dummy template molecularly imprinted polymers in separation of natural products / 中国中药杂志

The dummy template molecularly imprinted polymers not only has such characteristics of normal imprinted polymers as rapid identification, easy preparation, stable structure and multiple reuse, but also can imprint the compounds in natural products that are not suitable as direct template. Therefore, it has drawn more and more attention in the field of the study of natural products. This paper summarizes the methods for the selection of dummy template molecules by investigating the relevant literatures in the past ten years, analyzes the advantages and disadvantages of dummy template molecules in the practical application, and based on the types of natural products active ingredients, this paper is the first to review of the latest progress in extraction and separation of dummy template molecularly imprinted polymers. We believed that this paper could provide references for better applications of the dummy template molecularly imprinted polymers to extract and separate natural products.

Molecular imprinting technology and its application in terpenoids / 中国中药杂志

Molecular imprinting technology is widely used in the separation and analysis of compounds such as flavonoids, alkaloids and polyphenols, due to its high selectivity and specific recognition and so on. However, no much of attention has been paid to the terpenoids. This paper is aimed to not only review the effects of common synthetic elements such as functional monomers, cross-linking agents and porogens on the polymer properties, but also highlight the application of terpene molecular imprinting in solid phase extraction, sensor, membrane separation and chromatographic separation by means of statistical analysis of literature. Furthermore, the shortcomings and improvement directions are discussed.We believed that this paper could provide references for better applications of molecular imprinting techniques to the analysis of terpenoid compounds.

Efficient discovery and capturing of nNOS-PSD-95 uncouplers from Trifolium pratense / 中国中药杂志

Magnetic molecularly imprinted polymers(MMIPs) were prepared with ZL006 as template, acrylamide(AA) as the functional monomer, and acetonitrile as pore-forming agent; then Fourier transform infrared spectroscopy(FT-IR) and scanning electron microscopy(SEM) were used to characterize their forms and structures. Simultaneously, the MMIPs prepared previously were used as sorbents for dispersive magnetic solid phase extraction(DSPE) to capture and identify potential nNOS-PSD-95 uncouplers from extracts of Trifolium pratense and the the activities of the screened compounds were evaluated by the neuroprotective effect and co-immunoprecipitation test. The experiment revealed that the successfully synthesized MMIPs showed good dispersiveness, suitable particle size and good adsorption properties. Formononetin, prunetin and biochanin A were separated and enriched from Trifolium pratense by using the MMIPs as artificial antibodies and finally biochanin A was found to have higher cytoprotective action and uncoupling action according to the neuroprotective effect and co-immunoprecipitation test.

Contact lenses as drug controlled release systems: a narrative review / As lentes de contacto como sistema de libertação controlada de fármacos: uma revisão narrativa

ABSTRACT Topically applied therapy is the most common way to treat ocular diseases, however given the anatomical and physiological constraints of the eye, frequent dosing is required with possible repercussions in terms of patient compliance. Beyond refractive error correction, contact lenses (CLs) have, in the last few decades emerged as a potential ophthalmic drug controlled release system (DCRS). Extensive research is underway to understand how to best modify CLs to increase residence time and bioavailability of drugs within therapeutic levels on the ocular surface.These devices may simultaneously correct ametropia and have a role in managing ophthalmic disorders that can hinder CL wear such as dry eye, glaucoma, ocular allergy and cornea infection and injury. In this narrative review the authors explain how the ocular surface structures determine drug diffusion in the eye and summarize the strategies to enhance drug residence time and bioavailability. They synthesize findings and clinical applications of drug soaked CLs as DCRS combined with delivery diffusion barriers, incorporation of functional monomers, ion related controlled release, molecular imprinting, nanoparticles and layering. The authors draw conclusions about the impact of these novel ophthalmic agents delivery systems in improving drug transport in the target tissue and patient compliance, in reducing systemic absorption and undesired side effects, and discuss future perspectives.

RESUMO A forma mais frequente de aplicação terapêutica em oftalmologia consiste na instilação de gotas oculares, mas dadas as limitações anatómicas e fisiológicas do olho, é necessária dosagem frequente com possível repercussão na adesão do paciente à terapêutica. Nas últimas décadas, as lentes de contacto (CLs) têm surgido como um potencial sistema de libertação controlada de fármacos na superfície ocular (DCRS) para correção do erro refrativo. Está em curso uma extensa investigação para entender a melhor forma de modificar as CLs, de modo a aumentar o tempo de residência e a biodisponibilidade do medicamento na superfície ocular dentro de níveis terapêuticos. Ao corrigirem a ametropia, estes dispositivos poderão simultaneamente desempenhar um papel na gestão de perturbações oftalmológicas, tais como a síndrome do olho seco, glaucoma, alergia ocular e infecção corneana, que podem comprometer o porte seguro e confortável das CLs. Nesta revisão narrativa, os autores explicam como as estruturas da superfície ocular determinam a difusão de fármacos no olho e sintetizam as estratégias para aumentar a permanência e biodisponibilidade dos mesmos. Em seguida, apresentam os resultados e as aplicações clínicas das CLs embebidas em fármacos, como DCRS, através da incorporação de barreiras de difusão, de monómeros funcionais, da liberação controlada por iões, da impressão molecular, de nanopartículas e pelo processo camada sobre camada. Os autores concluem avaliando o impacto destes novos sistemas de entrega de agentes farmacológicos ao melhorar o seu transporte no tecido alvo, reduzindo a sua absorção sistémica e os seus efeitos colaterais indesejáveis, e discutem perspectivas futuras.

Preparation and evaluation of novel mesoporous molecular sieve of baicalin surface molecularly imprinted polymers / 中国中药杂志

Taking mesoporous molecular sieve MCM-41 as a substrate, baicalin (BA) as template, acrylamide (AM) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as a cross-linking agent, ethanol as solvent, under thermal polymerization initiator of azobis isobutyronitrilo (AIBN) , a kind of selective recognition of baicalin surface molecularly imprinted polymer was synthesized. The surface morphologies and characteristics of the MIPs were characterized by infrared spectroscopy (IR) and transmission electron microscope (TEM). The adsorption properties of polymer microsphere for the template were tested by the dynamic adsorption equilibrium experiments and static adsorption equilibrium experiments. The experiment showed that the imprinting process was successfully and the well-ordered one-dimensional pore structure of MCM-41 was still preserved. Furthermore, molecularly imprinted polymers had higher selective ability for BA, then provided a new method for the efficient separation and enrichment of baicalin active ingredients from medicinal plants Scutellaria baicalensis.

Exploration of research approaches of Chinese medicine's pharmacology based on "imprinting templates" (medical element) of supramolecules / 中国中药杂志

The paper, based on the previous publication as special impact of Chinese medicine theories on supramolcular chemistry, aims to analyze the natural origination for the Chinese medicine and to explain the special impact of "Qi chromatography" reaction on "imprinting templates" in supramolcular host of human being with Chinese medicine, in order to reveal the CM's properties of "medical element" with "imprinting templates" autonomisation generally took place in natural supramolecules, and also to discover that the CM's pharmacology are satisfied with its own approaches different form western pharmacology. It was decided, for CM's pharmacology guided by CM's theories, to "Qi chromatography" relations between the CM's ingredient groups and the meridian zang-fu viscera. The supramolcular chemistry played an all-through role in procession of making macro-regularities and special presentation on behavior of "Qi chromatography" impulse owning to the matching action of all kinds of ingredients on the meridian zang-fu viscera with similar "imprinting templates". The CM's pharmacology were guided by CM's theories, owing to its interpretation of supramolecular chemistry. The pharmacology was achieved to construct up completely on base of classical chemical single molecular bonds whereas the CM's pharmacology be configured to big building by way of "imprinting templates" as multi-weak bonds among "supramolecular society". CM's pharmacology was supramolcular pharmacology dealt with "molecular society" on the base of western pharmacology, and employed to double research approaches both math-physical quantitative representation on macroscope and qualitative analyses in microscope.

Application of molecularly imprinted technology for separation of PGG from Guizhi Fuling capsule / 中国中药杂志

1,2,3,4,6-penta-O-galloyl-D-glucose (PGG) is one of the main active compounds of Guizhi Fuling capsule. Molecularly imprinted polymers (MIP) have high affinity toward template molecules synthesized by molecularly imprinted technology for its specific combined sites, which can overcome the shortcoming of traditional separation methods, such as complex operation, low efficiency, using large quantity of solvent and environmental pollution. In this paper, surface molecularly imprinted polymer (SMIP) was prepared by surface imprinting with PGG as the template molecule. Its adsorption capacity was measured by the scatchard equation. The separation of PGG from Guizhi Fuling capsule at preparatived scale was achieved with molecularly imprinted polymer as stationary phase and the purity was 90.2% by HPLC. This method can be used to prepare PGG from Guizhi Fuling capsule with large capacity and is easy to operate. It provides a new method for efficient separation and purification for other natural products.

Recent advances and perspective in the study of the nano-reinforcing materials for molecular imprinting of proteins / 药学学报

Molecular imprinting technique (MIT) involves the synthesis of polymer in the presence of a template to produce complementary binding sites in terms of its size, shape and functional group orientation. Such kind of polymer possesses specific recognition ability towards its template molecule. Despite the rapid development of MIT over the years, the majority of the template molecules that have been studied are small molecules, while molecular imprinting of proteins remains a significant yet challenging task due to their large size, structural flexibility and complex conformation. This review, we summarized the research findings over the past years, and discussed the nano-reinforcing materials used to prepare molecular imprinting of proteins and the perspective of these nano-reinforcing materials.

Study on contribution of main components in Guizhi Fuling capsule based on molecular imprinting technique and activity screening / 中国中药杂志

To clarify the active components in Guizhi Fuling capsule in treatment of intrinsic dysmenorrhea, pelvic inflammation and hysteromyoma, main components were gradually knocked out from the capsules, the effects of knockout capsules on uterine contraction, TNF-α secretion, murine splenocytes (SPL) and hysteromyoma cells proliferation were evaluated, respectively. The inhibition of capsules on uterine contraction was weakened by gradient knockout of paeoniflorin, paeonol, and amygdalin. The suppression of capsulte on TNF-α secretion was reduced by gradient knockout of gallic acid, cinnamaldehyde, pentagalloylglucose, and pachyman. The promotion of SPL cells proliferation was reversed by gradient knockout of gallic acid, paeoniflorin, cinnamaldehyde, quercetin, and pachyman. The depression of capsules on hysteromyoma cells proliferation was attenuated by gradient knockout of paeoniflorin, paeonol, pentagalloylglucose, and albiflorin. In conclusion, the compounds mentioned-above could be the key active basis of Guizhi Fuling capsule in treatment of intrinsic dysmenorrhea, pelvic inflammation and hysteromyoma.

Determination of ochratoxin A in human urine by HPLC-FLD after cleaned-up by molecularly imprinted polymer solid phase extraction column / 药学学报

A method was developed for the determination of ochratoxin A (OTA) in human urine by HPLC-FLD after molecularly imprinted polymer solid phase extraction (MIP-SPE) column. After the pH being adjusted to 2.5 with 0.1 mol x L(-1) HC1, sample was cleaned up with MIP-SPE column for ochratoxin A, the analyte was analyzed by high performance liquid chromatography coupled with fluorescence detection (HPLC-FLD), and finally all the positive results were confirmed by LC-MS/MS. Recoveries from urine samples spiked with OTA at levels ranging from 2 to 20 ng x mL(-1) were 90.6%-101.9%, and RSDs were 0.1%-1.6%. Sixty-five volunteers living in Beijing took part in the study, of which 5 were found containing OTA in their urine and the highest value was 0.091 ng x mL(-1). The MIP-SPE column was firstly applied to purify and concentrate OTA in human urine, this method is simple, rapid and reliable and can be used to determine the contents of OTA in human urine.

Valoración de la impronta transoperatoria en la evaluación del ganglio centinela en mujeres con cáncer de mama en el Instituto Nacional de Enfermedades Neoplásicas (INEN), Lima-Perú / Assessment of intraoperative imprint in sentinel node evaluation in Women with breast Ccncer at the National Institute of Neoplastic Diseases (INEN), Lima-Perú

Objetivo: describir el valor de la impronta transoperatoria como método diagnóstico para la detección de metástasis del ganglio centinela en pacientes con cáncer de mama. Material y Métodos: se revisó las historias clínicas de 226 pacientes con cáncer de mama EC 0, I y II con axila cl¡nicamente negativa, sin quimioterapia neoadyuvante, sometidas a mapeo ganglionar y biopsia de ganglio centinela con sonda gamma y/o azul patente, a quienes se les realizó un examen transoperatorio de impronta citológica del ganglio centinela de abril del 2011 hasta marzo del 2012. Resultados: la edad promedio de las pacientes 54,5 años. Dos (0,9%) EC 0, 38 (16,8%) EC I, 170 (75,2%) EC IIA y 16 (7,1%) EC IIB. El resultado definitivo del ganglio centinela fue positivo en 78 (34,5%) casos y negativo en 148 (65,5%). Los resultados de la impronta transoperatoria mostraron una sensibilidad de 67,9% y una especificidad de 99,3%. El valor predictivo positivo fue 98,1% y el valor predictivo negativo de 85,5%. El índice de concordancia entre los resultados de la impronta y la prueba confirmatoria de metástasis se calculó en 0,72. Hubo 25 falsos negativos, 15 (60,0%) de ellos presentaron células aisladas y micro metástasis. Conclusiones: los resultados apoyan la validez y seguridad del método de impronta transoperatoria como prueba diagnóstica para la evaluación de metástasis del ganglio centinela en pacientes con cáncer de mama. Se observó un alto grado de concordancia entre los resultados de la impronta y la prueba confirmatoria para metástasis ganglionar.

Objetives: to evaluate the value of intraoperative imprint evaluation of the sentinel node as a method of diagnosis for node metastasis in breast cancer patients. Material and Methods: the clinical charts of 226 patients with breast cancer diagnosis in clinical stages 0, I and II were reviewed during April 2011 through March 2012. These patients had clinical negative axilla, none had neoadyuvant chemotherapy. They had a sentinel node biopsy with a prior lynphocintigraphy using Technecio 99 and had imprint citology in the operating room. Results: mean age was 54,5 years. Two (0,9%) were pathological stage 0, 38 (16,8%) I, 170 (75,2%) IIA and 16 (7,1%) IIB. We observed both a positive sentinel node in 78 (34,5%) cases and negative sentinel node in 148 (65,5%) cases. The imprint intraoperative results had a sensitivity of 67,9%, specificity of 99,3%, positive predictive value of 98,1% and negative predictive value of 85,5%. The index of concordance between de results of the imprint citology and the final pathology report was 0,72. There were 25 false negative cases, 15 (60,0%) from this group of patients only had micro metastasis or isolated cells. Conclusions: the results support the value and security of the intraoperative imprint cytology of the sentinel node as a diagnosis of node metastasis. There is a great level of concordance between the imprint results and the final pathology result.

Special influence of molecular imprinting technology on traditional Chinese medicine theories / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the influence of molecular imprinting phenomena of traditional Chinese medicines (TCMs) on basic theories of TCMs according to current situations of molecular imprinting technology and experimental studies.</p><p><b>METHOD</b>Fundamental principles of molecular imprinting theory were followed to analyze the material basis for TCM molecules to generate the imprinting phenomena, in order to find other material basis with more direct efficacy in line with the requirements of basic theories and modernization of TCMs.</p><p><b>RESULT</b>Compared with single-component structures, TCMs and their compound components could create super-molecular compounds through complexation, composition, chelation, inclusion, neutralization, self-assembly and chemical reaction. The material basis of TCMs was super-molecular compounds including single ingredients, and there was an inter-molecule imprinting phenomenon. Therefore, special attention should be paid to inter-super-molecule imprinting actions in studies on TCM property, quality control, processing, drug preparation and pharmacology. The compatibility of TCM compounds could significantly change the action.</p><p><b>CONCLUSION</b>The material basis of TCMs is super-molecular compounds based on single molecular groups. Super-molecules and molecular groups act rules, which is another difference between TCM compounds and single molecular drugs.</p>

Comparative study on two polymerization methods for preparing ginsenoside Rg1 molecularly imprinted polymer separating materials / 中国中药杂志

To obtain ginsenoside Rg1 molecularly imprinted polymer (MIP) separating materials with high selectivity, enrichment and adsorption performance through directional separation of ginsenoside Rg1 and analogues. In this study, MIPs were respectively prepared by precipitation polymerization and surface imprinted polymerization. Their adsorption performances were compared. The results showed that ginsenoside Rg1 MIPs prepared by the above two methods had a high adsorption performance to template molecules, with the maximum apparent adsorbing capacity of up to 27.74, 46. 80 mg x g(-1), respectively. Moreover, MIPs prepared by surface imprinted polymerization showed higher adsorption capacity than that by precipitation polymerization. The experimental results indicated that as for ginsenoside Rg1 with higher polarity, MIPs prepared by surface imprinted polymerization showed higher selectivity and adsorption performance, which provides provide important reference for preparing imprinted polymers with good adsorption performance with active molecules with strong polarity.

Study on directional separation of picroside II from extract of traditional Chinese medicine by molecularly imprinted technology / 中国中药杂志

Picroside II, separated from Chinese herbal medicine, is an active compound with neroprotective activity. Molecularly imprinted polymers (MIPs) have high affinity toward template molecules synthesized by molecularly imprinted technology for its specific combined sites, which can overcome the shortcomings of traditional separation methods, such as complex operation and low efficiency. In this paper, MIPs were prepared by precipitation polymerization with picroside II as the template molecule, 1-vinylimidazole (1-Vinyl) as functional monomer, ethylene glycol dimethacrylate (EDMA) as cross-linker. The morphology of MIPs was characterized by scanning electronmicroscope (SEM) and its static adsorption capacity was measured by the scatchard equation. The results showed that picroside II MIPs have spherical shape, and most of them are uniform in size. Furthermore, the maximum binding capacity (Q(max)) of MIPs is 3.02 mg x g(-1), higher than that of non-imprinted polymers (NIPs). This result indicated that picroside II MIPs with good morphology and high targeted affinity toward the template molecules can be prepared by precipitation polymerization, which can be used to separate picroside II and its analogies from extract of Chinese herbal medicine. In addition, this method has the advantages of good environment and simple operation, which might offer a novel method for the efficient separation of picroside II in the traditional herbal medicines.

Current progress in research on the nanomaterials for biological macromolecules recognition / 生物医学工程学杂志

The combination of nanotechnology and molecular imprinting technique, including their application research in biomedical domain, provides a new solution to the problem of the substitutes for antibodies, enzymes, and other native biological structures as well as cell bracket materials. Nanocavity biomaterials with recognition specificity imprinted by using proteins as templates have numerous applications in biotechnology, medicine and so on. This review presents the aspects of molecular imprinting nanostructure involved in the biomacromolecules imprinting, and it explores the precent developments and achievements of nanomaterials for molecular imprinting technology.

Recent advances and perspective in the study of the molecular imprinting of proteins / 药学学报

Molecular imprinting technique (MIT) involves the synthesis of polymer in the presence of a template to produce complementary binding sites in terms of its size, shape, and functional group orientation. Such kind of polymer possesses specific recognition ability towards its template molecule. Despite the rapid development of MIT over the years, the majority of the template molecules that have been studied are small molecules, while molecular imprinting of proteins remains a significant yet challenging task due to their large size, structural flexibility and complex conformation. In this review, we summarize the research findings over the past five years, and discuss the characteristics of the technique, the most recent progress and the perspective in the field of molecular imprinting of proteins.

Progress in research on LiquiChip technology in biomedical engineering / 生物医学工程学杂志

As a novel BioChip technique, LiquiChip technique uses fluorescent polystyrene beads as the carrriers of various probes, thus the related reactions of bio-molecules are in liquid system. LiquiChip technique is of use in the methods to detect bio-macromolecules, e. g. DNA detection, immunoassay, cytokine assay, hormone assay, environmental survey and analysis. In comparison to conventional biochip, LiquiChip presents the advantages of high-throughput, high sensitivity, high accuracy, fine repeatability, wide linear range, etc. Now LiquiChip technique is widely used in biomedical engineering field.

Molecularly imprinted solid phase extraction for trace analysis of diazinon in drinking water

Amongst organophosphate pesticides, the one most widely used and common environmental contaminant is diazinon; thus methods for its trace analysis in environmental samples must be developed. Use of diazinon imprinted polymers such as sorbents in solid phase extraction, is a prominent and novel application area of molecular imprinted polymers. For diazinon extraction, high performance liquid chromatography analysis was demonstrated in this study. During optimization of the molecular imprinted solid phase extraction procedure for efficient solid phase extraction of diazinon, Plackett-Burman design was conducted. Eight experimental factors with critical influence on molecular imprinted solid phase extraction performance were selected, and 12 different experimental runs based on Plackett-Burman design were carried out. The applicability of diazinon imprinted polymers as the sorbent in solid phase extraction, presented obtained good recoveries of diazinon from LC-grade water. An increase in pH caused an increase in the recovery on molecular imprinted solid phase extraction. From these results, the optimal molecular imprinted solid phase extraction procedure was as follows: solid phase extraction packing with 100 mg diazinon imprinted polymers; conditioning with 5 mL of methanol and 6 mL of LC-grade water; sample loading containing diazinon [pH=10]; washing with 1 mL of LC-grade water, 1 mL LC- grade water containing 30% acetonitrile and 0.5 mL of acetonitrile, respectively; eluting with 1 mL of methanol containing 2% acetic acid. The percentage recoveries obtained by the optimized molecular imprinted solid phase extraction were more than 90% with drinking water spiked at different trace levels of diazinon. Generally speaking, the molecular imprinted solid phase extraction procedure and subsequent high performance liquid chromatography analysis can be a relatively fast and proper approach for qualitative and quantitative analysis of diazinon in drinking water

Preparation and spectral characterization of apigenin molecularly imprinted polymer / 药学学报

An apigenin molecularly imprinted polymer was prepared by bulk polymerization using apigenin as template, acrylamide (AA) as a functional monomer, ethylene glycol dimethacrylate (EDMA) as a crosslinking agent, acetonitrile and N, N-dimethylformamide as porogenic solvents, and 2, 2'-azobisisobutyronitrile (AIBN) as an initiator. The interaction between template and functional monomer was proved by ultraviolet visible (UV) spectrophotometry and based on the results, appropriate reaction solvent was selected and the synthesizing process was estimated. The molecularly imprinted polymer structure was analyzed by Fourier Transform Infrared (FT-IR) spectrophotometry. The molecularly imprinted polymer was investigated in equilibrium binding experiment to evaluate its adsorption property, the results showed that the adsorption of apigenin on molecularly imprinted polymer is higher than that on blank polymer in the studied concentration range (0.1-2.5 mmol x L(-1)). Scatchard analysis showed that two classes of binding sites existed in the apigenin imprinted polymers, with their KD and Qmax estimated to be 2.52 x 10(-4), 0.54 x 10(-3) mmol x L(-1) and 2.65, 18.89 micromol x g(-1), respectively. Molecularly imprinted polymer showed higher affinity than blank polymer.

Removal of the template molecules from vinblastine-imprinted polymer / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the optimal condition for complete removal of the template molecules from vinblastine (VLB)-imprinted polymer.</p><p><b>METHOD</b>The prepared polymers were packed into the cartridges of solid-phase extraction column and washed by methanol-glacial acetic acid mixture with different proportions. The contents and recoveries of VLB in the effluents were determined.</p><p><b>RESULTS</b>Polymer extraction with methanol-glacial acetic acid (9:1, V/V) resulted in VLB recovery of 91.73%, but template bleeding was observed because of incomplete VLB removal. Using methanol-glacial acetic acid (6:4, V/V) as the extraction solvent, the recovery of VLB reached 98.03% with less solvents and extract times. The polymers could selectively adsorb VLB through non-covalent interactions and still exhibited strong affinity for the template molecule but not for the structural analogue vincristine after extraction with methanol-glacial acetic acid (6:4, V/V).</p><p><b>CONCLUSION</b>Methanol-glacial acetic acid (6:4, V/V) is an ideal extract solvent for complete template molecule removal from the polymers, and the processed polymers possess stable capacity of specific recognition and selectivity to the template.</p>