Pharmacokinetics of salvianolic acid B,rosmarinic acid and Danshensu in rat after pulmonary administration of Salvia miltiorrhiza polyphenolic acid solution

A sensitive and accurate LC–MS/MS method was established for quantifying salvianolic acid B (Sal B), rosmarinic acid (Ros A) and Danshensu (DA) in rat plasma. Salvia miltiorrhiza polyphenolic acid (SMPA), active water‐soluble ingredients isolated and purified from Salvia miltiorrhiza Bge included Sal B, Ros A and DA. The pharmacokinetic analysis of Sal B, Ros A and DA after pulmonary administration of SMPA solution to rat was performed by LC–MS/MS. Results from the pharmacokinetic studies showed that the peak concentration of DA was 21.85 ± 6.43 and 65.39 ± 3.83 ng/mL after pulmonary and intravenous administration, respectively. DA was not detected at 2 h after administration. The absolute bioavailabilities of Sal B and Ros A were respectively 50.37 ± 27.04 and 89.63 ± 12.16% after pulmonary administration of 10 mg/kg SMPA solution in rats. The absolute bioavailability of Sal B increased at least 10‐fold after pulmonary administration, compared with oral administration. It was concluded that the newly established LC–MS/MS method was suitable for describing the pharmacokinetic characteristics of Sal B, Ros A and DA in rat after pulmonary administration of SMPA solution. The data from this study will provide a preclinical insight into the feasibility of pulmonary administration of SMPA.     

Internal plasticization of poly(vinyl) chloride using glutamic acid as a branched linker to incorporate four plasticizers per anchor point

Internal plasticization of polyvinyl chloride (PVC) using thermal azide‐alkyne Huisgen dipolar cycloaddition between azidized PVC and electron‐poor acetylenediamides incorporating a branched glutamic acid linker resulted in incorporation of four plasticizing moieties per attachment point on the polymer chain. A systematic study incorporating either alkyl or polyethylene glycol esters provided materials with varying degrees of plasticization, with depressed T_g values ranging from ?1 °C to 62 °C. Three interesting trends were observed. First, T_g values of PVC bearing various internal plasticizers were shown to decrease with increasing chain length of the plasticizing ester. Second, branched internal plasticizers bearing triethylene glycol chains had lower T_g values compared to those with similar length long‐chain alkyl groups. Finally, thermogravimetric analysis of these internally plasticized PVC samples revealed that these branched internal plasticizers bearing alkyl chains are more thermally stable than similarity branched plasticizers bearing triethylene glycol units. These internal tetra‐plasticizers were synthesized and attached to PVC‐azide in three simple synthetic steps. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 1821–1835     

A molecular dynamics simulation of the chemisorption of the optical isomers of propranolol on the graphitic electrode modified with melamine,cyanuric, and isocyanuric acids

To demonstrate the nature of the interaction of optical isomers of propranolol with the surface of the graphitic electrode modified with melamine, uracil, cyanuric, and isocyanuric acids, we have performed molecular dynamics simulations of the four‐component systems with variable modifier's molecules. We have considered the possible formation of complexes between the propranolol and modifier's molecules, covering the electrode approximated as the graphene surface. Our simulations demonstrate that the l ‐isomer in aqueous solutions is bonded to the electrode surface stronger than its d ‐counterpart; hence, the difference in analytical signals arises. Different strengths of bonding of the propranolol enantiomers to the surface modifiers are caused by the different intramolecular interactions taking place in the molecules of d ‐ and l ‐isomers. Thus, we have computationally shown that the modification of the graphite surface with melamine, uracil, cyanuric, and isocyanuric acids allows for increasing the sensitivity of the electrode toward the propranolol enantiomers and using the modified graphitic electrodes for the detection of its d ‐ and l ‐forms.     

Applications of magnetic materials separation in biological nanomedicine

As a result of their advantages for superparamagnetic properties, good biocompatibility, and high binding capacity, functionalized magnetic materials became widely popular over the past couple of decades, being applied on large scale in various processes of sample preparation for biomedicine. In this work, we perform an in‐depth review on the current progress in the field of magnetic bead separation, discussing in detail the physical basis of this process, various synthesis methods and surface modification strategies. We place special focus of attention as well on the latest applications of magnetic polymer microspheres in cell separation, protein purification, immobilized enzyme, nucleic acid separation, and extraction of bioactive compounds with low molecular weight. Existing problems are highlighted and possible trends of magnetic separation techniques for biomedicine in the future are proposed.     

Surface Charge‐Reversible Tubular Micromotors for Extraction of Nucleic Acids in Microsystems

Extraction of nucleic acids in microsystems is of significance for biomedical applications, but the current extraction methods generally require sophisticated microchannels and external equipment, hindering their practical applications. In this work, we have demonstrated a simple, versatile and efficient approach to extract nucleic acids in microsystems by developing cationic branched polyethyleneimine (PEI)‐functionalized tubular micromotors. The as‐developed tubular micromotors are fabricated by a two‐step process combining the template‐assisted electrodeposition and carbodiimide chemistry, and contain an inner catalytic Pt layer, a middle magnetic Ni layer and an outer cationic PEI layer. They exhibit autonomous bubble‐propelled motion in aqueous hydrogen peroxide solutions, which can be guided by an external magnetic field, and the surface charges can be reversibly modulated by changing the pH value of the solution. Consequently, the as‐developed tubular micromotors can selectively absorb nucleic acids from acidic solutions and desorb them into alkaline solutions, leading to the extraction of nucleic acids with high efficiency without external stirring. Furthermore, they can be operated in a microchannel chip without the aid of a pumping system. Our results indicate that this PEI‐functionalized tubular micromotor platform provides a novel, simple and versatile microsystem nucleic acid extraction technology, holding considerable promise for important practical applications.     

Aqueous Phase Sensing of Fe3+ and Ascorbic Acid by a Metal–Organic Framework and Its Implication in the Construction of Multiple Logic Gates

A new Hf^IV‐based metal‐organic framework with UiO‐66 topology was synthesized via a one‐step solvothermal method by using 3‐methyl‐4‐phenylthieno[2,3‐b]thiophene‐2,5‐dicarboxylic acid (H₂MPTDC) as a ligand. The MOF material showed a high stability in a broad pH range (from pH 2 to pH 12) in an aqueous medium. The presence of hydrophobic methyl and phenyl substituents in the carboxylic acid ligand and strong Hf?O bond play crucial roles in its stability. The new MOF material was systematically characterized by various techniques such as XRPD, N₂ sorption, thermogravimetric analyses and FT‐IR spectroscopy. The photophysical properties of the MOF material were also examined by steady‐state and time‐resolved fluorescence studies. It was observed that the blue fluorescence of the MOF material was selectively quenched in the presence of Fe³⁺ ion in pure aqueous medium. A mechanistic study disclosed that quenching occurs via a strong inner filter effect (IFE) arising from Fe³⁺ ion in aqueous medium. Interestingly, the fluorescence of the MOF material can be recovered by elimination of the IFE of Fe³⁺ ion via reduction of Fe³⁺ ion by ascorbic acid (AA). Based on the fluorescence recovery by AA, a MOF based on‐off‐on probe was developed for the sensing of Fe³⁺ ion and AA in aqueous medium. Inspired by this reversible sensing event, we demonstrate basic (NOT, OR, YES, INHIBIT and IMP) and higher integrated logic operations utilizing this fluorescent MOF. This MOF‐based logic systems could be potentially used for next‐generation logic‐gate based analytical applications as well as for the detection and discrimination of targeted molecules in various complex domains.     

Acetate chitosan with CaCO3 doping form tough hydrogel for hemostasis and wound healing

In recent years, chitosan has been applied for wound management due to its properties of biocompatibility, biodegradability, antimicrobial activity, and low immunogenicity. But the poor water solubility in neutral pH limited its further application in clinical wound healing. To overcome this problem, acetate chitosan was developed and approved as commercial products for wound healing. However, the acidity of acetate chitosan was potentially allergenic, and the poor mechanical properties of its formed hydrogels also hindered the therapeutic efficacy in wound care. In this study, CaCO₃ was simply doped into acetate chitosan to form the wound dressing. After absorbing water, the H⁺ of acetate chitosan reacted with CaCO₃ to release Ca²⁺, resulting in acidity decreased. The production of Ca²⁺ and residue of CaCO₃ cross‐linked with chitosan to form a tough hydrogel by electrostatic interaction. The physical characteristics, swelling, mechanical testing, and blood clotting were evaluated. The results in vitro demonstrated that after doping CaCO₃ into acetate chitosan, the mechanical properties and blood clotting of the formed hydrogel were increased. Then, the evaluation of hydrogels in vivo revealed that it can also accelerate the wound healing by promoting re‐epithelization and collagen deposition. This simple way by doping CaCO₃ into acetate chitosan can increase wound healing, and it can also broad the application of acetate chitosan in clinical use.     

Mass‐Spectrometric Observation of Counter Anion Production in SU‐8 Exposed to UV Light and its Use for Dill C Parameter Determination

Photopolymerization is a phenomenon that is the basis of much of today's microfabrication technology and intense research is conducted to improve its control and the characteristics of end products for a variety of applications. The design of microscopic structures often relies on the accurate knowledge and modeling of photopolymer's behavior upon exposure, i.e. the Dill parameters, for each radiation species of interest and therefore the development of flexible characterization techniques is of great importance. SU‐8 is a popular compound that is representative of a whole class that relies on cationic polymerization, where an acid is obtained via photolysis of an onium salt during exposure. Here we report on the observation of SbF₆^? via laser desorption mass spectrometry on SU‐8 exposed to UV light at the wavelength of 365 nm and demonstrate that the yield of this counter‐anion as a function of exposure is consistent with the Dill C parameter value available in the literature. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 967–972     

Molecularly imprinted hydrogels for sustained release of sunitinib in breast cancer therapy

The present work reports on the synthesis of a molecularly imprinted polymer (MIP) based on methacrylic acid and ethylene glycol dimethacrylate for sunitinib delivery. Sunitinib (SUT) is a tyrosine kinase inhibitor used in many cancer diseases. Like the majority of the anticancer drugs, SUT suffers of a low bioavailability, and at the same time, it is characterized by a narrow therapeutic window. In order to reduce drug systemic toxicity, we synthesized a MIP‐based drug delivery system for SUT‐controlled release. MIP was obtained by bulk polymerization through the so‐called noncovalent approach. Rebinding experiments were performed to evaluate the success of the imprinting process and the ability of MIP to bind in a specific and selective fashion the template molecule. Resulting data showed that sunitinib rebinding percentage was 70%, while nonimprinted polymer (NIP) rebinding percentage was 46%. A not significant difference was observed between MIP and NIP in semaxanib binding experiments. Moreover, the drug release profiles were studied for both MIP and NIP. A sustained release was observed from sunitinib‐loaded MIP during 24 hours, reaching 58% after 6 hours and 76% at the end‐point. NIP, on the contrary, released almost 90% of the loaded drug within 6 hours. Furthermore, the drug carrier was tested in vitro against MCF‐7 cells, in which the cytotoxic effect of sunitinib released from MIP reached the maximum after 72 hours, while NIP completed its effect within 48 hours. These results demonstrated that molecularly imprinted polymers are suitable systems for SUT release.     

Mussel‐inspired decoration of Ni(OH)2 nanosheets on 2D MoS2 towards enhancing thermal and flame retardancy properties of poly(lactic acid)

In the present work, a facile and environmental method was developed to fabricate the novel functionalized MoS₂ hybrid. Firstly, MoS₂ nanosheets were coated with polydopamine (PDA) through the self‐polymerization of dopamine (MoS₂‐PDA) in a buffer solution. Then the decoration of Ni(OH)₂ on the MoS₂‐PDA was synthesized because of the strong affinity of Ni²⁺ with hydroxyl groups in PDA. Finally, the as‐synthesized MoS₂‐PDA@Ni(OH)₂ was introduced into poly(lactic acid) (PLA) matrix to explore flame retardancy, thermal stability, and crystalline property of the composites. As confirmed by X‐ray diffraction (XRD), Fourier‐transform infrared spectrometer (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA), the MoS₂ nanosheets were dually modified with PDA and Ni(OH)₂ without destroying the original structures. The thermal degradation of PLA with MoS₂‐PDA@Ni(OH)₂ generated a notably higher yield of char. Moreover, the crystallization rate of composites is higher than neat PLA. The cone calorimeter test revealed that the introduction of 3% MoS₂‐PDA@Ni(OH)₂ resulted in lower Peak Heat Release Rate (PHRR) (decreased by 21.7%). Thus, the research provided an innovative functionalization method for manufacturing PLA composites with high performances.