•Synthesis of carboxymethyl dextran-coated magnetoliposomes.•Good stability in serum and high drug loading ability for doxorubicin.•Enhanced drug release under low-frequency alternating magnetic field.•High relaxivity ratio of r2 to r1 as T2-weighted contrast agent in MR imaging.•A potential carrier for targeting diagnostic-therapy for cancers.The aim of this work was to construct carboxymethyl dextran (CMD)-coated magnetoliposomes (MLs), another stealth MLs alternative to PEGylated MLs, for theranostic application. Particularly, the on-demand release of CMD-MLs under low-frequency alternating magnetic field (LF-AMF) was studied. We found that as-prepared MLs exhibited good stability and high drug loading ability for doxorubicin (DOX). Cytotoxicity assay against human neuroblastoma SH-SY5Y cells showed that the DOX-loaded CMD-MLs were less toxic than free DOX due to the sustained release of DOX. However, the release of DOX-loaded CMD-MLs was enhanced by low-frequency alternating magnetic field without hyperthermia generation. The MLs also acted as an efficient T2-weighted contrast agent during in vitro MRI measurements. The above results provide useful information on in vivo diagnostic/therapeutic efficacy of DOX-loaded CMD-MLs for some cancers, such as brain cancers.

In this work, carboxymethyl dextran (CMD), a polysaccharidic dextran derivative with well-known biocompatibility and biodegradability, was used to modify curcumin-loaded liposomes for improving the anticancer efficacy of curcumin. The CMDylated curcumin-loaded liposomes (CMD-Cur-Lip) were successfully prepared and characterized in comparison with unmodified and two PEGylated curcumin-loaded liposomes. The results showed that: (1) the encapsulation efficiency of curcumin in the liposomes was improved after being modified with CMD; (2) all the curcumin-loaded liposomes displayed controlled release characteristics; (3) the CMD-Cur-Lip demonstrated improved cell cytotoxicity against cancer cells, as compared to other liposomal formulations and free curcumin; (4) CMD-Cur-Lip exhibited the highest cellular uptake as compared to other liposomal formulations.

•We prepared imprinted-like biopolymeric micelles (IBMs) via green process.•IBMs showed imprinted-like property for the polyphenol analogous drugs.•Water solubility of curcumin was increased by 5 × 104-fold after encapsulation.•Curcumin-loaded IBMs exhibited superior growth inhibition against tumor cells.•IBMs could effectively improve the oral bioavailability of curcumin.To enhance the solubility and improve the bioavailability of hydrophobic curcumin, a new kind of imprinted-like biopolymeric micelles (IBMs) was designed. The IBMs were prepared via co-assembly of gelatin–dextran conjugates with hydrophilic tea polyphenol, then crosslinking the assembled micelles and finally removing the template tea polyphenol by dialysis. The obtained IBMs show selective binding for polyphenol analogous drugs over other drugs. Furthermore, curcumin can be effectively encapsulated into the IBMs with 5 × 104-fold enhancement of aqueous solubility. We observed the sustained drug release behavior from the curcumin-loaded IBMs (CUR@IBMs) in typical biological buffers. In addition, we found the cell uptake of CUR@IBMs is much higher than that of free curcumin. The cell cytotoxicity results illustrated that CUR@IBMs can improve the growth inhibition of HeLa cells compared with free curcumin, while the blank IBMs have little cytotoxicity. The in vivo animal study demonstrated that the IBMs could significantly improve the oral bioavailability of curcumin.

We developed a pH-dependent etching method for the synthesis of stable fluorescent silver nanoclusters (AgNCs) in aqueous solution. The AgNCs emit at 530 nm when excited at 380 nm and can be used for Hg2+ detection with a low detection limit and high selectivity.

Three new hydroxyl-substituted Schiff-bases containing ferrocenyl moieties were synthesized, and their antioxidant and anticancer activities were evaluated. Among the synthesized hydroxyl-substituted Schiff-bases, compound 1 containing both ferrocenyl and o-dihydroxyl groups exhibits the highest antioxidant and anticancer activities. Flow cytometric analysis showed that compound 1 is capable of disturbing the cancer cell cycle and inducing more cells to be arrested in G2 phase. The excellent biological activities of compound 1 are attributed to the presence of both ferrocenyl and o-dihydroxyl groups. The ferrocenyl moiety has dual functions in compound 1, i.e., increasing the lipophilicity and lowering the redox potentials of o-dihydroxyl groups. In addition, compound 1 could reversibly bind with HSA mainly via a mechanism involving the formation of complexes, in which hydrophobic interaction is the main acting force. Thus, compound 1 containing both ferrocenyl and o-dihydroxyl groups is a potential antioxidant with anticancer activity.

A novel ratiometric fluorescent probe A1, based on excited-state intramolecular proton transfer (ESIPT) mechanism, for the detection of benzoyl peroxide (BPO) was designed and synthesized. A1 was employed for determining BPO in food and pharmaceutical samples with good sensitivity and high selectivity.

Alzheimer’s disease (AD) is the most common cause of dementia, and currently there is no clinical treatment to cure it or to halt its progression. Aggregation and fibril formation of β-amyloid peptides (Aβ) are central events in the pathogenesis of AD. Many efforts have been spent on the development of effective inhibitors to prevent Aβ fibrillogenesis and cause disaggregation of preformed Aβ fibrils. In this study, the conjugates of ferrocene and Gly-Pro-Arg (GPR) tripeptide, Boc-Gly-Pro-Arg(NO2)-Fca-OMe (4, GPR–Fca) and Fc-Gly-Pro-Arg-OMe (7, Fc–GPR) (Fc: ferrocene; Fca: ferrocene amino acid) were synthesized by HOBT/HBTU protocol in solution. These ferrocene GPR conjugates were employed to inhibit Aβ1–42 fibrillogenesis and to disaggregate preformed Aβ fibrils. The inhibitory properties of ferrocene GPR conjugates on Aβ1–42 fibrillogenesis were evaluated by thioflavin T (ThT) fluorescence assay, and confirmed by atomic force microscopy (AFM) analysis. The interaction between the ferrocene GPR conjugates and Aβ1–42 was monitored by electrochemical means. Our results showed that both GPR and GPR–Fca can significantly inhibit the fibril formation of Aβ1–42, and cause disaggregation of the preformed fibrils. As expected, GPR–Fca shows stronger inhibitory effect on Aβ1–42 fibrillogenesis than that of its parent peptide GPR. In contrast, Fc–GPR shows no inhibitory effect on fibrillogenesis of Aβ1–42. Furthermore, GPR–Fca demonstrates significantly protection against Aβ-induced cytotoxicity and exhibits high resistance to proteolysis and good lipophilicity.The ferrocene GPR conjugates were synthesized in solution. GPR–Fca shows stronger inhibitory effect on Aβ1–42 fibrillogenesis and disaggregation of existing Aβ1–42 mature fibrils. Moreover, GPR–Fca demonstrates significant protection against Aβ-induced cytotoxicity and high resistance to proteolysis.

Nanoencapsulation is a promising method to improve the bioavailability of tea polyphenol (TPP). In this work, we adopted a green process to develop a new kind of complex coacervation core micelles (C3Ms) based on biopolymers for efficient tea polyphenol delivery. First, gelatin–dextran conjugate was synthesized using Maillard reaction. Then the C3Ms were produced by mixing gelatin–dextran conjugate with TPP. Variable factors on the self-assembly of the C3Ms were investigated. Under optimal conditions, the obtained C3Ms are of nanosize (average 86 nm in diameter) with narrow distribution. The formation of the C3Ms is attributed to hydrophobic interaction and hydrogen bonding instead of electrostatic interaction. Transmission electron microscope (TEM) and scanning electron microscope (SEM) results showed that C3Ms have a spherical shape with core–shell structure. ζ-Potential measurement suggested that the core is composed of gelatin with TPP, whereas the shell is composed of dextran segments. The encapsulation efficiency of the C3Ms is pH-independent, but the loading capacity is controllable and as high as 360 wt % (weight/weight of protein). In addition, the C3Ms show sustained release of TPP in vitro. MTT assay revealed that the C3Ms have comparable or even stronger cytotoxicity against MCF-7 cells than free TPP.

Liposomes have been widely used as promising drug delivery systems. The stabilization of liposomes however remains challenging, especially when surface binding properties are involved. In this work, we reported carboxymethyl dextran-coated liposomes (CMD-LIPs), in an attempt to improve their stability, surface binding and release properties. Firstly, we introduced hydrophobic oleyl groups onto CMD, and then used the amphiphilic CMD, phosphatidylcholine and cholesterol to prepare the CMD-LIPs. Surface plasmon resonance measurements confirmed that CMD-LIPs inhibited non-specific protein adsorption and exhibited active targeting when coupling ligands to the liposomal surface. Moreover, doxorubicin (DOX)-loaded CMD-LIPs displayed a sustained and pH-responsive drug release profile. MTT assay revealed that the cytotoxicity of DOX-loaded CMD-LIPs on HeLa cells was time- and concentration- dependent. Additionally, the DOX-loaded CMD-LIPs were highly stable in serum media and against dilution, long-term storage and lyophilization.

This paper describes the fabrication and application of a complex electrode – Nafion film coating ferrocenylalkanethiol (FcC11SH) and encapsulated glucose oxidase (GOD) on a gold electrode. FcC11SH is employed as a mediator enabling the electron transfer between GOD and the electrode, GOD is encapsulated in polyacrylamide gel to improve the stability of the enzyme, and the Nafion film is coated on the modified electrode to eliminate interferents such as ascorbic acid, uric acid and acetaminophen in amperometric glucose detection. It is noticed that such a complex electrode exhibits excellent catalytic activity for glucose oxidation, and preserves the native structure of GOD and therefore its enzymatic activity. The encapsulated GOD retains more than 80% of its original biocatalytic activity even after 24 days, much longer than that of naked GOD molecules attached directly to the electrode. The oxidation peak current at the modified electrode shows a linear relationship with the glucose concentration in the range from 0.05 to 20 mM with a detection limit of 2.4 μM. In addition, the electrode displays a rapid response and good reproducibility for glucose detection, and has been successfully employed for glucose detection in blood plasma samples.

Three new hydroxyl-substituted Schiff-bases containing ferrocenyl moieties were synthesized, and their antioxidant and anticancer activities were evaluated. Among the synthesized hydroxyl-substituted Schiff-bases, compound 1 containing both ferrocenyl and o-dihydroxyl groups exhibits the highest antioxidant and anticancer activities. Flow cytometric analysis showed that compound 1 is capable of disturbing the cancer cell cycle and inducing more cells to be arrested in G2 phase. The excellent biological activities of compound 1 are attributed to the presence of both ferrocenyl and o-dihydroxyl groups. The ferrocenyl moiety has dual functions in compound 1, i.e., increasing the lipophilicity and lowering the redox potentials of o-dihydroxyl groups. In addition, compound 1 could reversibly bind with HSA mainly via a mechanism involving the formation of complexes, in which hydrophobic interaction is the main acting force. Thus, compound 1 containing both ferrocenyl and o-dihydroxyl groups is a potential antioxidant with anticancer activity.