An injectable collagen peptide-based hydrogel with desirable antibacterial, self-healing and wound-healing properties based on multiple-dynamic crosslinking.

Conventional collagen-based hydrogels as wound dressing materials are usually lack of antibacterial activity and easily broken when encountering external forces. In this work, we developed a collagen peptide-based hydrogel as a wound dressing, which was composed of adipic acid dihydrazide functionalized collagen peptide (Col-ADH), oxidized dextran (ODex), polyvinyl alcohol (PVA) and borax via multiple-dynamic reversible bonds (acylhydrazone, amine, borate ester and hydrogen bonds). The injectable hydrogel exhibited satisfactory self-healing ability, antibacterial activity, mechanical strength, as well as good biocompatibility and biodegradability. In vivo experiments demonstrated the rapid hemostasis, accelerated cell migration, and promoted wound healing capacities of the hydrogel. These results indicate that the multifunctional collagen peptide-based hydrogel has great potentials in the field of wound dressings.

[Research progress and maturity assessment of continuous manufacturing of traditional Chinese medicine].

The pharmaceutical manufacturing model is gradually changing from intermittent manufacturing to continuous manufacturing and intelligent manufacturing. This paper briefly reviewed the supervision and research progress in continuous pharmaceutical manufacturing in China and abroad and described the definition and advantages of continuous pharmaceutical manufacturing. The continuous manufacturing of traditional Chinese medicine(TCM) at the current stage was summarized in the following three terms: the enhancement of the continuity of intermittent manufacturing operations, the integration of continuous equipment to improve physical continuity between units, and the application of advanced process control strategies to improve process continuity. To achieve continuous manufacturing of TCM, the corresponding key technologies, such as material property characterization, process modeling and simulation, process analysis technology, and system integration, were analyzed from the process and equipment, respectively. It was proposed that the continuous manufacturing equipment system should have the characteristics of high speed, high response, and high reliability, "three high(H~3)" for short. Considering the characteristics and current situation of TCM manufacturing, based on the two dimensions of product quality control and production efficiency, a maturity assessment model for continuous manufacturing of TCM, consisting of operation continuity, equipment continuity, process continuity, and quality control continuity, was proposed to provide references for the application of continuous manufacturing technology for TCM. The implementation of continuous manufacturing or the application of key continuous manufacturing technologies in TCM can help to systematically integrate advanced pharmaceutical technology elements and promote the uniformity of TCM quality and the improvement of production efficiency.

Sub-50 nm core-shell nanoparticles with the pH-responsive squeezing release effect for targeting therapy of hepatocellular carcinoma.

The development of drug delivery systems with high drug loading capacity, low leakage at physiological pH, and rapid release at the lesion sites remains an ongoing challenge. In this work, core-shell poly(6-O-methacryloyl-D-galactose)@poly(tert-butyl methacrylate) (PMADGal@PtBMA) nanoparticles (NPs) of sub-50 nm are facilely synthesized by reversible addition-fragmentation chain transfer (RAFT) soap-free emulsion polymerization with the assistance of 12-crown-4. A hydrophilic poly(methacrylic acid) (PMAA) core can then be revealed after deprotection of the tert-butyl groups, which is negatively charged and can adsorb nearly 100% of incubated doxorubicin (DOX) from a solution at pH 7.4. The physical shrinkage of PMAA chains below pH 6.0 endows the core with the squeezing effect, therefore realizing rapid drug release. It is demonstrated that the DOX release rate of PMADGal@PMAA NPs at pH 5 was 4 times that at pH 7.4. Cellular uptake experiments confirm the high targeting ability of the galactose modified PMADGal shell to human hepatocellular carcinoma (HepG2) cells. The fluorescence intensity of DOX in HepG2 cells is 4.86 times that of HeLa cells after 3 h incubation. Moreover, 20% cross-linked NPs show the highest uptake efficiency by HepG2 cells due to their moderate surface charge, size and hardness. In summary, both the core and the shell of PMADGal@PMAA NPs promise the rapid site-specific release of DOX in HepG2 cells. This work provides a facile and an effective strategy to synthesize core-shell NPs for hepatocellular carcinoma targeting therapy.

Galactosylated Core-Shell Nanoparticles with pH/GSH Dual Sensitivity for Targeting Hepatocellular Carcinoma.

Galactosylated core-shell nanoparticles (NPs) with diameters of sub-50 nm were fabricated in one pot by reversible addition-fragmentation chain transfer (RAFT) soap-free emulsion polymerization. Their galactosylated shells and acidic cores endow them with high targeting and drug loading efficiencies, respectively. Morever, the physical shrinkage and cleavage of the disulfide cross-linked NPs can realize the rapid release of loaded doxorubicin (DOX) under pH 5.0 and reduced glutathione (GSH) conditions. The combination of these excellent properties resulted in an even lower IC50 of DOX-loaded NPs than free DOX, demonstrating that this platform would be promising in targeting the therapy of hepatocellular carcinoma.

Retraction of "Thermoresponsive Gigaporous Microspheres Facilitate the Efficient Refolding of Recombinant Nitrilase Inclusion Bodies".

[This retracts the article DOI: 10.1021/acsomega.0c00432.].

One-Pot Fabrication of Hierarchically Bicontinuous Polystyrene Monoliths with Homogeneous Skeletons and Glycopolymer Surfaces.

The hierarchically bicontinuous polystyrene monoliths (HBPMs) with homogeneous skeletons and glycopolymer surfaces are fabricated for the first time based on the medium internal phase emulsion (MIPE) templating method via activator generated by electron transfer for atom transfer radical polymerization (AGET ATRP). The synergistic self-assembly of amphiphilic diblock glycopolymer (ADG) and Pluronic F127 (PF127) at the oil/water interface via hydrogen bonding interaction contributes to the formation of bicontinuous MIPE with deformed neighboring water droplets, resulting in the highly interconnected HBPM after polymerization. There is a bimodal pore size distribution in the HBPM, that is, through pores (150-5000 nm) and mesopores (10-150 nm). The HBPMs as prepared show excellent biocompatibility, homogeneous skeletons, strong mechanical strength, and high bed permeability, overcoming the practical limitations of the second generation of polystyrene (PS) monoliths. Glycoprotein concanavalin A (Con A) can be easily and quickly separated by the HBPM in hydrophilic interaction chromatography (HILIC) mode. These results suggest the HBPMs have great potentials in catalysis, separations, and biomedical applications.

[Formulation of technical guidelines in line with characteristics and principles of traditional Chinese medicine changes to improve quality of such preparations--interpretation of Technical guidelines for the study of pharmaceutical changes in traditional Chinese medicines].

In leading the high-quality development of Chinese medicine preparations, it is an important link to formulate the scientific, reasonable, and feasible guidelines for the change of Chinese medicines in accordance with the change characteristics and principles of the Chinese medicines is an important work to promote the Technical guidelines for the study of pharmaceutical changes in traditional Chinese medicines was formed by a broad consensus based on the characteristics and research results of the pharmaceutical changes in Traditional Chinese Medicines(TCM)with the principles of science and risk management. This guideline has clarified the basic principles and requirements for the evaluation of changes in TCM, specified the research and verification work of common change scenarios, defined the boundaries of changes in TCM, and proposed to encourage the use of new technologies, new methods, and new excipients that meet product characteristics. It will definitely promote the quality improvement and the secondary development of TCM. In this article, the revision background and main content of the guideline were introduced, and the main features of the Guideline were analyzed, in order to provide references for the industry.

In-situ grafting temperature-responsive hydrogel as a bifunctional solid-phase microextraction coating for tunable extraction of biomacromolecules.

A temperature-responsive solid-phase microextraction (SPME) coating was prepared via in-situ atom transfer radical polymerization (ATRP) method. By controlling the temperature of solution below and above the lower critical solution temperature (LCST) of the coating, it can switch between hydrophilic and hydrophobic, thus providing a convenient approach for the selective extraction of analytes with different polarities. The average extraction amount of temperature-responsive coating for polar analytes is about 1.5-fold to that of non-polar ones below LCST, and vice versa. Effective extraction of three biomacromolecules was also obtained by controlling the temperature below or above LCST. The adsorption capacity of the coating for the hydrophilic biomacromolecules at 15 °C is 1.5-2 folds that of 50 °C, whereas the adsorption capacity of the coating to BSA at 50 °C is about 3 folds that of 15 °C. This approach holds great promise for SPME because it provides a simple strategy to prepare bifunctional coatings for various applications.

Cytotoxic triterpenoid glycosides from leaves of Cyclocarya paliurus.

Three previously undescribed dammarane triterpenoid glycosides (1-3) along with five known analogues (4-8) were isolated from the leaves of Cyclocarya paliurus. Their structures and configurations were determined on the basis of comprehensive spectroscopic analyses, chemical hydrolysis and DFT GIAO 13C NMR calculation. All the isolates were evaluated cytotoxic activities against seven human cancer cell lines (MCF-7, PC-3, Du145, NCI-H1975, PC-9, SKVO3 and HepG2). Moreover, compound 4 showed a wide spectrum of cytotoxicity against human cancer cells with IC50 values ranging from 11.31 to 29.51 µM.

Thermoresponsive Gigaporous Microspheres Facilitate the Efficient Refolding of Recombinant Nitrilase Inclusion Bodies.

In order to assist the refolding of recombinant nitrilase inclusion bodies, a series of thermoresponsive media were prepared by grafting poly(N-isopropylacrylamide-co-butyl-methacrylate) [P(NIPAM-co-BMA)] brushes onto PS microspheres with various particles and pore sizes via an atom transfer radical polymerization (ATRP) method. The effects of particle sizes, pore sizes, and brush grafting amounts of thermoresponsive microspheres on nitrilase refolding were investigated preliminarily. The results showed that the PS-P(NIPAM-co-BMA) microspheres with the medium particle size (74 µm), gigapore size (320 nm), and high grafting amount (35.6 mg/m2) were the most effective candidates. The final nitrilase activity yield could be up to 84.5% with a high initial protein concentration (1 mg/mL) at 30 °C, which was 52.5% higher than that of a simple dilution refolding method at the initial protein concentration (0.1 mg/mL). After the refolding process, the PS-P(NIPAM-co-BMA) microspheres can be easily separated by self-precipitation, and the activity yield of nitrilase still reached 74.5% after being reused for five batches. These results indicated that the thermoresponsive gigaporous medium was an ideal alternative as an artificial chaperone.

Mesorhizobium carbonis sp. nov., isolated from coal bed water.

A Gram-stain negative, aerobic, motile, short rod-shaped bacterium, designated as B2.3T, was isolated from coal bed water collected from Jincheng, Shanxi Province, China. The strain was able to grow at 10-40 °C (optimum 28-30 °C), pH 4.0-10.0 (optimum 7.0), and in the presence of 0-5.0% NaCl (optimum 3.0%, w/v). Phylogenetic analysis based on the 16S rRNA and concatenated housekeeping gene recA, atpD and glnA sequences showed strain B2.3T belongs to the genus Mesorhizobium, with Mesorhizobium oceanicum B7T as the closely related type strain. Strain B2.3T exhibited ANI value of 77.5% and GGDC value of 21.5% to M. oceanicum B7T. The major fatty acids were identified as summed feature 8 (C18:1ω7c and/or C18:1ω6c) and 11-methyl C18:1ω7c. The major polar lipids were found to consist of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and an unidentified aminophospholipid. The predominant ubiquinone was identified as Quinone 10. Phenotypic and biochemical analysis results indicated that strain B2.3T can be distinguished from closely related type strains. On the basis of phenotypic, genotypic and chemotaxonomic characteristics, strain B2.3T is concluded to represent a novel species in the genus Mesorhizobium, for which the name Mesorhizobium carbonis sp. nov. is proposed. The type strain is B2.3T (=CGMCC 1.15730T = KCTC 52461T).

Swollen Micelles for the Preparation of Gated, Squeezable, pH-Responsive Drug Carriers.

Natural variations in pH levels of tissues in the body make it an attractive stimuli to trigger drug release from a delivery vehicle. A number of such carriers have been developed but achieving high drug loading combined with low leakage at physiological pH and tunable controlled release at the site of action is an ongoing challenge. Here we report a novel strategy for the synthesis of entirely hydrophilic stimuli-responsive nanocarriers with high passive loading efficiency of doxorubicin (DOX), which show good stability at pH 7 and rapid tunable drug release at intracellular pH. The particles (Dh = 120-150 nm), are prepared by cross-linking the core of swollen micelles of the triblock copolymer poly[poly(ethylene glycol) methyl ether methacrylate-b-N,N'-di(methylamino)ethyl methacrylate-b-tert-butyl methacrylate] (poly(PEGMEM A)-b- PDMAEMA-b-PtBMA)). After subsequent deprotection of the tert-butyl groups a hydrophilic poly(methacrylic acid) (PMAA) core is revealed. Due to the negative charge in the acidic core the particles absorb 100% of the DOX from solution at pH 7 at up to 50 wt % DOX/polymer, making them extremely simple to load. Unlike other systems, the DMAEMA "gating" shell ensures low drug leakage at pH 7, whereas physical shrinkage of the MAA core allows rapid release below pH 6. The particles deliver DOX with high efficiency to human pancreatic cancer AsPC-1 cell lines, even lowering the IC50 of DOX. As the particles are stable as a dry powder and can be loaded with any mixture of positively charged drugs without complex synthetic or purification steps, we propose they will find use in a range of delivery applications.

Inherently fluorescent polystyrene microspheres for coating, sensing and cellular imaging.

Commercially available polystyrene (PS) fluorescent microspheres are widely used in biological field for tracing, in vivo imaging and calibration of flow cytometry, among other applications. However, these particles do suffer from some drawbacks such as the leakage and photobleaching of organic dyes within them. In the present study, inherently fluorescent properties of PS based microspheres have been explored for the first time. Here we find that a simple chloromethylation reaction endows the polystyrene particles with inherent fluorescence without any subsequent conjugation of an external fluorophore. A possible mechanism for fluorescence is elucidated by synthesizing and investigating p-ethylbenzyl chloride, a compound with similar structure. Significantly, no photobleaching or leaking issues were observed owing to the stable structure of the microspheres. Chloromethylated PS (CMPS) microspheres can keep their perpetual blue fluorescence even in dry powder state making them attractive as a potential coating material. Furthermore, the chloromethyl groups on CMPS microspheres make them very convenient for further functionalization. Poly(ethylene glycol) (PEG) grafted microspheres showed good biocompatibility and negligible cytotoxicity, and could be used to image intracellular Fe3+ due to the selective fluorescence quenching effect of aqueous Fe3+ in cytoplasm.

Thermo- and pH-responsive polymer brushes-grafted gigaporous polystyrene microspheres as a high-speed protein chromatography matrix.

Dual thermo- and pH-responsive chromatography has been proposed using poly(N-isopropylacrylamide-co-butyl methacrylate-co-N,N-dimethylaminopropyl acrylamide) (P(NIPAM-co-BMA-co-DMAPAAM)) brushes grafted gigaporous polystyrene microspheres (GPM) as matrix. Atom transfer radical polymerization (ATRP) initiator was first coupled onto GPM through Friedel-Crafts acylation with 2-bromoisobutyryl bromide. The dual-responsive polymer brushes were then grafted onto GPM via surface-initiated ATRP. The surface composition, gigaporous structure, protein adsorption and dual-responsive chromatographic properties of the matrix (GPM-P(NIPAM-co-BMA-co-DMAPAAM) were characterized in detail. Results showed that GPM were successfully grafted with thermoresponsive cationic polymer brushes and that the gigaporous structure was well maintained. A column packed with GPM-P(NIPAM-co-BMA-co-DMAPAAM presented low backpressure, good permeability and appreciable thermo-responsibility. By changing pH of the mobile phase and temperature of the column in turn, the column can separate three model proteins at the mobile phase velocity up to 2528cmh(-1). A separation mechanism of this matrix was also proposed. All results indicate that the dual thermo- and pH-responsive chromatography matrix has great potentials in 'green' high-speed protein chromatography.

A colorimetric assay for measuring iodide using Au@Ag core-shell nanoparticles coupled with Cu(2+).

Au@Ag core-shell nanoparticles (NPs) were synthesized and coupled with copper ion (Cu(2+)) for the colorimetric sensing of iodide ion (I(-)). This assay relies on the fact that the absorption spectra and the color of metallic core-shell NPs are sensitive to their chemical ingredient and dimensional core-to-shell ratio. When I(-) was added to the Au@Ag core-shell NPs-Cu(2+) system/solution, Cu(2+) can oxidize I(-) into iodine (I2), which can further oxidize silver shells to form silver iodide (AgI). The generated Au@AgI core-shell NPs led to color changes from yellow to purple, which was utilized for the colorimetric sensing of I(-). The assay only took 10 min with a lowest detectable concentration of 0.5 µM, and it exhibited excellent selectivity for I(-) over other common anions tested. Furthermore, Au@Ag core-shell NPs-Cu(2+) was embedded into agarose gels as inexpensive and portable "test strips", which were successfully used for the semi-quantitation of I(-) in dried kelps.

Preparation and characterization of a thermoresponsive gigaporous medium for high-speed protein chromatography.

A high-speed thermoresponsive medium was developed by grafting poly(N-isopropylacrylamide-co-butyl methacrylate) (P(NIPAM-co-BMA)) brushes onto gigaporous polystyrene (PS) microspheres via surface-initiated atom transfer radical polymerization (ATRP) technique, which has strong mechanical strength, good chemical stability and high mass transfer rate for biomacromolecules. The gigaporous structure, surface chemical composition, static protein adsorption, and thermoresponsive chromatographic properties of prepared medium (PS-P(NIPAM-co-BMA)) were characterized in detail. Results showed that the PS microspheres were successfully grafted with P(NIPAM-co-BMA) brushes and that the gigaporous structure was robustly maintained. After grafting, the nonspecific adsorption of proteins on PS microspheres was greatly reduced. A column packed with PS-P(NIPAM-co-BMA) exhibited low backpressure and significant thermo-responsibility. By simply changing the column temperature, it was able to separate three model proteins at the mobile phase velocity up to 2167 cm h(-1). In conclusion, the thermoresponsive polymer brushes grafted gigaporous PS microspheres prepared by ATRP are very promising in 'green' high-speed preparative protein chromatography.

Coating gigaporous polystyrene microspheres with cross-linked poly(vinyl alcohol) hydrogel as a rapid protein chromatography matrix.

Gigaporous polystyrene (PS) microspheres were hydrophilized by in situ polymerization to give a stable cross-linked poly(vinyl alcohol) (PVA) hydrogel coating, which can shield proteins from the hydrophobic PS surface underneath. The amination of microspheres (PS-NH2) was first carried out through acetylization, oximation and reduction, and then 4,4'-azobis (4-cyanovaleric acid) (ACV), a polymerization initiator, was covalently immobilized on PS-NH2 through amide bond formation, and the cross-linked poly(vinyl acetate) (PVAc) was prepared by radical polymerization at the surfaces of ACV-immobilized PS microspheres (PS-ACV). Finally, the cross-linked PVA hydrogel coated gigaporous PS microspheres (PS-PVA) was easily achieved through alcoholysis of PVAc. Results suggested that the PS microspheres were effectively coated with cross-linked PVA hydrogel, where the gigaporrous structure remained under optimal conditions. After hydrophilic modification (PS-PVA), the protein-resistant ability of microspheres was greatly improved. The hydroxyl-rich PS-PVA surface can be easily derivatized by classical chemical methods. Performance advantages of the PS-PVA column in flow experiment include good permeability, low backpressure, and mechanical stability. These results indicated that PS-PVA should be promising in rapid protein chromatography.

PEG-chitosan-coated iron oxide nanoparticles with high saturated magnetization as carriers of 10-hydroxycamptothecin: preparation, characterization and cytotoxicity studies.

A magnetic nano-sized carrier for 10-hydroxycamptothecin (HCPT) was prepared by using Fe(3)O(4) nanoparticles as cores and chitosan (CS) as a polymeric shell by a novel reverse ultrasonic emulsification method. Poly(ethylene glycol) (PEG) chains were then coupled onto the magnetic particles (CS-Fe(3)O(4)) to improve their biocompatibility (PEG-CS-Fe(3)O(4)). HCPT was loaded onto PEG-CS-Fe(3)O(4) by a subtle precipitation method. Under optimum conditions, the CS-Fe(3)O(4) was close to spherical in shape with an average size of 174 nm and a high saturated magnetization. After coupling PEG chains, the unspecific adsorption of bovine serum albumin (BSA) on PEG-CS-Fe(3)O(4) decreased significantly. The drug loading content and loading efficiency were 9.8-11.8% and 49-59% for magnetic composite nanoparticles, respectively. HCPT-loaded magnetic composite nanoparticles showed sustained release profiles up to 48 h, and the cumulative release amount of HCPT from nanoparticles at 45°C increased significantly compared to that at 37°C. Cytotoxicity assay suggests that CS-Fe(3)O(4) does not exhibit noteworthy cytotoxicity against HepG2 cells, but the antitumor activities of HCPT-loaded magnetic composite nanoparticles against HepG2 cells increased significantly in comparison with that of pristine HCPT powder. These results reveal the promising potential of PEG-CS-Fe(3)O(4) as a stable magnetic targeting drug carrier in cancer therapy.

A novel matrix derivatized from hydrophilic gigaporous polystyrene-based microspheres for high-speed immobilized-metal affinity chromatography.

Agarose coated gigaporous polystyrene microspheres were evaluated as a novel matrix for immobilized-metal affinity chromatography (IMAC). With four steps, nickel ions were successfully immobilized on the microspheres. The gigaporous structure and chromatographic properties of IMAC medium were characterized. A column packed with the matrix showed low column backpressure and high column efficiency at high flow velocity. Furthermore, this matrix was used for purifying superoxide dismutase (SOD), which was expressed in Escherichia coli (E. coli) in submerged fermentation, on an Äkta purifier 100 system under different flow velocities. The purity of the SOD from this one-step purification was 79% and the recovery yield was about 89.6% under the superficial flow velocity of 3251 cm/h. In conclusion, all the results suggested that the gigaporous matrix has considerable advantages for high-speed immobilized-metal affinity chromatography.

Galactosylated nanocrystallites of insoluble anticancer drug for liver-targeting therapy: an in vitro evaluation.

AIM: Low solubility in water has become an intrinsic property of many anticancer drugs, which poses a hurdle in the translation from the bench to the clinic. In this study, we developed a facile method to prepare 10-hydroxycamptothecin (HCPT) nanocrystallites and testified their feasibility for liver-targeting therapy. MATERIALS & METHODS: HCPT nanocrystallites were prepared under the soft template effect of galactosylated chitosan. The internalization profile, intracellular trafficking, drug activity and cell viability were evaluated by exposing these nanocrystallites to human hepatocellular carcinoma HepG2 cells. RESULTS: Galactosylated chitosan located on the HCPT nanocrystallites not only stabilized the formulation in aqueous medium, but also enhanced the cellular internalization through an asialoglycoprotein receptor-mediated pathway. These nanocrystallites also exhibited the advantages of nuclear entry and active HCPT delivery, and consequently better anticancer cytotoxicity could be achieved. CONCLUSION: These data strongly support the superior properties of galactosylated HCPT nanocrystallites on liver-targeting therapy.