Preparation and characterization of molecularly imprinted polymers based on ß-cyclodextrin-stabilized Pickering emulsion polymerization for selective recognition of erythromycin from river water and milk.

Molecularly imprinted polymers were prepared via ß-cyclodextrin-stabilized oil-in-water Pickering emulsion polymerization for selective recognition and adsorption of erythromycin. The synthesized molecularly imprinted polymers were spherical in shape, with diameters ranging from 20 to 40 µm. The molecularly imprinted polymers showed high adsorption capacity (87.08 mg/g) and adsorption isotherm data fitted well with Langmuir model. Adsorption kinetics study demonstrated that the molecularly imprinted polymers acted in a fast adsorption kinetic pattern and the adsorption features of molecularly imprinted polymers followed a pseudo-first-order model. Adsorption selectivity analysis revealed that molecularly imprinted polymers had a much better specificity for erythromycin than that for spiramycin or amoxicillin, and the relative selectivity coefficient values on the bases of spiramycin and amoxicillin were 3.97 and 3.86, respectively. The Molecularly imprinted polymers also showed a satisfactory reusability after four times of regeneration. In addition, molecularly imprinted polymers exhibited good adsorption capacities for erythromycin under complicated environment, that is, river water and milk. These results proved that the as-prepared molecularly imprinted polymers is a potent absorbent for selective recognition of erythromycin, and therefore it may be a promising candidate for practical applications, such as wastewater treatment and detection of erythromycin residues in food.

Fabrication, GSH-responsive drug release, and anticancer properties of thioctic acid-based intelligent hydrogels.

Injectable hydrogels are potential local drug delivery systems since they contain plenty of water and soft like biological tissues. Such hydrogels could be injected directly into the tumor site where the drug is released under the tumor microenvironment. However, drug loaded hydrogels for cancer treatment based on lipoic acid (natural small molecule) have not been exploited. Here, a novel poly(lipoic acid)-poly(ethylene glycol) (PEG-PTA) hydrogels were prepared through a two-step reaction. The hydrogels contained disulfide bonds, so they could be degraded via the thiol exchange reaction with the abundant GSH in the tumor microenvironment, and subsequently release the drug. The results in vitro and at cellular level showed that the hydrogels were degraded and released the drugs only in the presence of GSH. Therefore, the injectable GSH-responsive hydrogels are promising to be served as an intelligent drug delivery system for cancer treatment.

Current methods and prospects of coronavirus detection.

SARS-COV-2 is a novel coronavirus discovered in Wuhan in December 30, 2019, and is a family of SARS-COV (severe acute respiratory syndrome coronavirus), that is, coronavirus family. After infection with SARS-COV-2, patients often experience fever, cough, gas prostration, dyspnea and other symptoms, which can lead to severe acute respiratory syndrome (SARS), kidney failure and even death. The SARS-COV-2 virus is particularly infectious and has led to a global infection crisis, with an explosion in the number of infections. Therefore, rapid and accurate detection of the virus plays a vital role. At present, many detection methods are limited in their wide application due to their defects such as high preparation cost, poor stability and complex operation process. Moreover, some methods need to be operated by professional medical staff, which can easily lead to infection. In order to overcome these problems, a Surface molecular imprinting technology (SM-MIT) is proposed for the first time to detect SARS-COV-2 virus. For this SM-MIT method, this review provides detailed detection principles and steps. In addition, this method not only has the advantages of low cost, high stability and good specificity, but also can detect whether it is infected at designated points. Therefore, we think SM-MIT may have great potential in the detection of SARS-COV-2 virus.

Capsule-like molecular imprinted polymer nanoparticles for targeted and chemophotothermal synergistic cancer therapy.

Selective cancer cell targeting, controlled drug release, easy construction and multiple therapeutic modalities are some of the desirable characteristics of drug delivery systems. We designed and built simple capsule-like molecular imprinted polymer (MIP)-based nanoparticles for targeted and chemo-photothermal synergistic cancer therapy. Using dopamine (DA) as functional monomer, cross-linking agent as well as photo-thermal agent, ZIF-8 (zeoliticimidazolate framework-8) as drug carrier, epitope of EGFR (epidermal growth factor receptor) as template molecules, molecular imprinted polymer (MIP) drug carrier was constructed. The ability of MIP layer to bind to EGFR epitope endowed the MD (DOX@MIP) particles to recognize EGFR-overexpressing cancer cells, while the pH-responsiveness and photothermal conversion ability of PDA (polydopamine) achieved chemo-photothermal synergistic effects upon NIR irradiation. Taken together, the MD nanoparticles integrated cancer cell targeting recognition, intelligent drug release, biocompatibility and chemo-photothermal effects, and is therefore a promising tool for targeted cancer therapy with minimal toxicity to normal cells, as well as tumor imaging.

Micelles via self-assembly of amphiphilic beta-cyclodextrin block copolymers as drug carrier for cancer therapy.

We developed intelligent, star-shaped amphiphilic ß-cyclodextrin (ß-CD) co-polymer nanocarriers to circumvent the poor drug loading and water-solubility of ß-CD. The secondary hydroxyl groups of ß-CD were methylated to improve solubility, and the primary hydroxyl groups were conjugated with mPEG-b-PCL-SH through disulfide linkage to amplify the hydrophobic cavity and enhance the stability of the nanocarrier. A series of amphiphilic ß-CD block copolymers (CCPPs) differing in molecular weights were synthesized that could self-assemble into core-shell nanospheres measuring 50-70 nm in water. The different CCPP carriers were screened for their drug loading, encapsulation and release efficiencies, and CCPP-2 showed the highest drug loading capacity of 31.9% by weight. These nanocarriers accumulated at the tumor site through the EPR effect and released the drug in a controlled manner in the reductive tumor microenvironment, with negligible premature leakage and side effects. Therefore, CCPP-2 shows significant potential as a smart and efficient nanovehicle for anticancer drug delivery.

Amphipathic ß-cyclodextrin nanocarriers serve as intelligent delivery platform for anticancer drug.

A novel glutathione-responsive (GSH-responsive) star-like amphiphilic polymer (C12H25)14-ß-CD-(S-S-mPEG)7 (denoted as CCSP) was designed for efficient antitumor drug delivery. The amphiphilic ß-cyclodextrin (ß-CD) self-polymerize in water to form a sphere with a diameter of 40-50 nm. The secondary hydroxyl groups of ß-CD were modified by dodecyl to form a hydrophobic core and the primary hydroxyl groups of ß-CD were decorated with PEG through disulfide bond to form a hydrophilic shell. Since the hydrophobic cavity of ß-CD was maintained, the hydrophobic core formed by dodecyl as well as cavity of ß-CD provided CCSP with a loading content as high as 39.6 wt%. Importantly, DOX@CCSP exhibited low drug leakage and negligible cytotoxicity in non-reductive physiological environment, while it showed rapid release and high cytotoxicity in reductive tumorous environment via the breakage of disulfide bond. In view of the above-mentioned advantages of DOX@CCSP nanocarriers such as high loading content, proper size, favorable stimulus-response release performance and low leakage, it is believed that CCSP may offer great potential to be used as an intelligent nanocarrier for anticancer drug delivery.

Polyphenolic compounds from the leaves of Koelreuteria paniculata Laxm.

From the fresh leaves of Koelreuteria paniculata Laxm (Sapindaceae), four new compounds, named ethyl p-trigallate (1), 3''-O-galloyl-4'-O-galloyl-4-O-galloyl-gallic acid (2), ethyl p-heptagallate (3) and 3''-galloylquercitrin (4), together with 12 known compounds namely catechin (5), galloylepicatechin (6), isorhamnetin (7), kaempferol-3-O-arabinopyranoside (8), quercetin-3'-O-beta-D-arabinopyranoside (9), quercitrin (10), methyl p-digallate (11), methyl m-digallate (12), p-digalloyl acid (13), m-digalloyl acid (14), hyperin (15) and kaempferol-3-O-alpha-L-rhamnoside (16) were isolated by extensive column chromatographic separation. Their structures were elucidated on the basis of chemical and spectroscopic methods. Compound 9 was not reported previously with pyranoside of arabinose at C-3'. Compounds 4 and 9 possessed the activity for PTK inhibition.