CiteSpace knowledge map of gut microbiota research involving traditional Chinese medicine in recent twenty years / 中国中药杂志

We employed bibliometrics to comprehensively study the hotspots and frontiers of gut microbiota research involving traditional Chinese medicine(TCM), aiming to provide new ideas for the subsequent research in this field. The studies of gut microbiota with TCM published from January 1, 2002 to December 31, 2021 were retrieved from CNKI, Wanfang, VIP and Web of Science(WoS). After data screening and cleaning, CiteSpace 5.8.R3 was used to visualize and analyze the authors, journals, and keywords. A total of 1 119 Chinese articles and 815 English articles were included in the study. The period of 2019-2021 witnessed the surge in the number of articles published in this field, being the peak research period. TAN Zhou-jin and DUAN Jin-ao were the authors publishing the most articles in Chinese and English, respectively. The two authors ranked top in both Chinese and English articles, playing a central role in this research field. The top five Chinese and English journals in this field had a large influence in the international research field. High-frequency keywords and keyword clustering showed that the research hotspots in this field were concentrated in four areas: trial and clinical research on the regulation of gut microbiota in disease treatment by TCM, metabolic transformation of Chinese medicines by gut microbiota, and the effect of TCM added to feed on the gut microbiota and growth performance of animals. The study of gut microbiota structure in patients with different TCM syndromes, as well as that of TCM combined with probiotics/flora transplantation in the treatment of diseases, can provide new ideas for clinical diagnosis and traditional drug treatment of diseases and has great research space and research value in the future.

Strategies and reflections on platelet-based targeted therapy for tumor / 药学学报

In the past few decades, our understanding of platelets has made great progress. Platelets play an unexpected central role in cancer and greatly affect the behavior of cancer cells. At the same time, the physiology and phenotype of platelets are also affected by cancer cells. Therefore, platelet-based tumor targeted therapy strategies have attracted the attention of researchers, but the limitations of their application require more attention. In this paper, the strategies of platelet-based tumor targeted therapy are summarized, and the strategies of platelet mimicking nanocarrier delivery, platelet hitch riding, platelet membrane coating biomimetic and engineered platelet targeting are mainly introduced. The easy activation, hard storage and unknown functional and phenotypic changes of platelets were discussed. At the same time, the strategy of platelet-based targeted tumor therapy is reviewed from theoretical basis and practical application. The development potential of platelets in the field of tumor diagnosis and treatment is discussed, which will provide some theoretical reference for the study of platelet-related tumor diagnosis and targeted therapy.

Pharmacodynamics of liposomes modified with different chain length of sialic acid derivatives / 药学学报

A large number of experimental and clinical data indicates that tumor-associated macrophages (TAMs) were involved in the whole process of tumor growth, invasion and metastasis. Like macrophages in other tissues, TAMs originate from blood monocytes, which are recruited to the tumor tissues by cytokines and then differentiated into TAMs. It is interesting that the monocytes overexpress siglec receptor in their surface, which has a high binding specificity to sialic acid (SA). From this point of view, we hypothesize that if SA was used as a ligand in the surfaces of drug delivery systems, SA would enhance the targeting efficiency to monocytes, and thus to achieve a higher specificity to TAMs. In our previous study, an SA derivative of SA-octadecylamine (SA-18) was synthesized and was found to enhance cytotoxicity on TAMs in vitro. The chain length is a critical factor for SA efficiency in liposomes and it has a significant influence on the TAM targeting effects of the carriers. So in this study, four kinds of different chain length of SA fatty amine derivatives were synthesized, including SA-18, SA-hexadecylamine (SA-16), SA-tetradecylamine (SA-14) and SA-dodecylamine (SA-12), and were modified on the surfaces of blank liposomes (BLK-SnL, n=18, 16, 14, 12) and pixantrone maleate-loaded liposomes (Pix-SnL, n=18, 16, 14, 12). TAM targeting effects of these SA derivatives were evaluated by acute toxicity and antitumor efficacy in vivo. The results of acute toxicity experiments showed that the toxicities of the SA derivatives deceased gradually with the reduction in the length of lipophilic chain. The in vivo antitumor efficacies of SA-modified blank liposomes showed that these blank formulations had no effect on the tumor inhibition except BLK-S14L (61.4%±18.8%), and BLK-S16L even promoted the tumor growth (-31.7%±13.1%, the 18th day). The in vivo antitumor efficacies of SA-modified Pix liposomes showed that the tumor inhibition effects were Pix-S18L (97.4%±2.1%) > Pix-S14L (73.1%±21.1%) > Pix-S12L (53.9%±17.8%) > Pix-S16L (32.9%). Because of the relatively strong binding ability of SA-18, it was hard to fall off from the liposomes in the transport process, leading to a good TAM targeting ability and less toxicity to the normal tissues. Meanwhile, 50% of the mice in Pix-S18L group showed "tumor shedding" and "wound healing" phenomena without recurrence in two months following the treatment. Therefore, SA-18 is the most potential TAM targeting material among these SA fatty amine derivatives.

"PEG dilemma" for liposomes and its solving approaches / 药学学报

Polyethylene glycol (PEG) is extensively used to increasing the in vivo and in vitro stability of liposomes. However, PEGylated liposomes also produce some negative effects with further research, such as low cellular uptake, poor "endosomal escape" of pH sensitive liposome (PSL) and accelerated blood clearance (ABC) phenomenon, and this situation is referred as the "PEG dilemma". "PEG dilemma" posed severe challenges for the targeted delivery of PEGylated liposomes-loaded anticancer drugs, effective intracellular release of PEGylated PSL-encapsulated gene and protein drugs, and repeated administration of PEGylated liposomes. Therefore, it is urgent to solve the "PEG dilemma". This review focused on the definition, classification of "PEG dilemma", and discussed several possible approaches to overcome "PEG dilemma".

Effect of polyethylene glycol-lipid derivatives on the stability of grafted liposomes / 药学学报

It is reported that polyethylene glycol-lipid (PEG-lipid) derivatives increase liposomes stability, prolong the blood circulation of liposomes, enhance their tumor-targeting efficiency, and improve drug efficacy. Therefore, it is of great importance to investigate the influence of modified PEG-lipid derivatives on the physical, chemical, and biological characteristics of liposomes for the promotion of dealing with the existed problems, such as the accelerated blood clearance (ABC) phenomenon when repeated intravous injection at a certain time-interval, and developing novel targeted pharmaceutical preparations. In this review, the effects of modified PEG-lipid derivatives were summarized in many aspects. It indicats that the chemical bonds (amide, ether, ester, and disulfide) between PEG and lipid, as well as the species of lipids, such as the commonly used phosphatidylethanolamine, cholesterol, and diacylglycerol have substantial effects on the grafted liposomes stability in vitro and in vivo. Besides, the properties of lipids (the fatty acid chain length and saturation) and the groups (methoxy, carboxylic and amino) at the distal ends of the PEG chains were also considered to be important factors. In the end, the influence of the average molecular weight of PEG and the molar ratio of PEG-lipid derivatives in the total lipid were further focused.

Advances in the study of polymeric micelles used in oral administration / 药学学报

Polymeric micelles which are self-assembled from amphiphilic copolymers are thermodynamically stable, and they can solubilize hydrophobic drugs by the hydrophilic core. Many excellent active compounds are confined because of general low oral bioavailability due to poor solubility. Take into account from the two points above, polymeric micelles may be used as proper oral carrier to improve the dissolubility of hydrophobic drugs, and enhance the permeation though gastrointestinal tract, therefore, the pharmacodynamics is elevated. Meanwhile, the segments in copolymers are multivariate, so many kinds of micelles can be obtained, such as, pH- or thermo- sensitive as well as mucoadhesive ones. The modified micelles can alter drug release profiles while solubilizing them, that is why the oral bioavailability increase further. In this review, recent progress of polymeric micelles used in oral administration is summarized, and the prospect of polymeric micelles' application in this field is also evaluated.

Recent advances in the study of accelerated blood clearance phenomenon of PEGylated liposomes / 药学学报

It is generally believed that liposomes modified with polyethylene glycol (PEG) have no or lower immunogenicity. However, based on many recent literatures, when the PEGylated liposomes were repeatedly applied to the same animal, the immune responses occurred. The first injection of PEGylated liposomes resulted in a reduction in the circulation time and an increase in hepatic and splenic accumulation of the second dose of PEGylated liposomes in a time-interval, which was called "accelerated blood clearance (ABC)" phenomenon. Such immunogenicity of PEGylated liposomes presents a barrier in the research of liposomal formulations and their use in the clinics. This review focused on the definition, the method of verification, the development of the reason for ABC phenomenon, influencing factors of ABC phenomenon, and discussed if other PEGylated nanocarriers also induce ABC phenomenon.

Inhibitory effect of cucurbitacin E on the proliferation of ovarian cancer cells and its mechanism / 癌症

<p><b>BACKGROUND AND OBJECTIVE</b>There are various biological activities of cucurbitacin E (CuE), including antitumor effect, anti-chemical carcino-genesis, liver protection, and enhancement of the immunity, and so on. This study was to investigate the effect of CuE on proliferation inhibition and apoptosis induction of ovarian cancer ES-2 cells, and to explore the mechanism.</p><p><b>METHODS</b>ES-2 cells were treated with different concentrations of CuE for 24, 48, and 72 h, respectively. Cell proliferation was tested by MTT assay. The morphologic changes and apoptosis were observed under inverted microscope and fluorescent microscope. Cell cycle distribution was evaluated with flow cytometry. The expression of p-STAT3 was determined by Western blot.</p><p><b>RESULTS</b>The number of ES-2 significantly decreased as the concentration of CuE increased or the time prolonged. Flow cytometry analysis showed that the ratio of ES-2 cells treated 1 micromol/L CuE for 24 h increased both in S phase [from (10.55+/-0.91)% to ( 16.31 +/- 4.61) % ] and in G(2)/M phase [from (18.53+/-1.43)% to (58.34 +/- 5.77)%], while decreased in G(1) phase [from (73.13 +/-4.70)% to (23.12 +/- 5.45)%] (P<0.05). The marked morphological changes of cell apoptosis were clearly observed in ES-2 cells treated with CuE. CuE inhibited the STAT3 phosphorylation in ES-2 cell in a dose- dependent manner.</p><p><b>CONCLUSION</b>CuE can inhibit ES-2 proliferation and induce apoptosis and cell cycle arrest, which may be related to the decreased expression of the intracellular STAT3 phosphorylation.</p>

Recent advances in the study of cleavable PEG-lipid derivatives modifying liposomes / 药学学报

Polyethylene glycol (PEG) lipid derivatives could increase the stability of liposomes in vivo and in vitro and prolong the circulation time of liposomes in vivo. However, the chemical bond between PEG and lipid was so stable that liposomes modified with traditional PEG-lipid derivatives could not release their contents at targeted tissue immediately and the pharmacodynamic effect was reduced. The concept of cleavable PEG-lipid was raised in recent years and these PEG-lipid derivatives could break under physiological or pathological condition. The cleavable PEG-lipid derivatives could prolong the circulation time of liposomes, and after arriving at targeted location, PEG fragment had cleaved from the surface of liposomes, so liposomes could bind with pathological cells and release contents into cells. Removal of the protective polymer layer is necessary once the liposome close to the tumour to allow to fuse and release drug. Attempts have been made to increase the circulation time and reconstitute the cellular affinity of liposomes by incorporating PEG-lipid derivatives. This review focused on the kinds of cleavable PEG-lipid derivatives, types of cleavage, the application feature to liposomes and the advantages and localizations.

Preparation of docetaxel-loaded pH-sensitive block copolymer micelles / 药学学报

Basing on the synthesis of pH-sensitive amphiphilic block copolymer poly (2-ethyl-2-oxazoline)-poly (D, L-lactide)(PEOz-PDLLA), this paper presents the preparation of docetaxel-loaded pH-sensitive block copolymer micelles using film dispersion method. The critical micelle concentration (CMC) was measured by pyrene fluorescent probe technique. The entrapment efficiency and drug-loaded amount were determined by HPLC. The morphology, diameter and surface potential of the micelles were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS) and zeta potential analyzer, respectively. The in vitro release behavior of DTX from polymeric micelles was investigated using dialysis method. The results indicated that the CMC, drug-loaded amount and entrapment efficiency of the micelles was 1.0 x 10(-3) g x L(-1), 15.0% and 91.1%, respectively. The micelles had a narrow size distribution, with a mean diameter of 28.7 nm. The micelle was globular-shaped and its zeta potential was (1.19 +/- 0.12) mV. In pH 7.4 PBS, docetaxel was released in a sustained manner from the micelles; while in PBS at pH 5.0, drug was released more rapidly, which suggested the pH-sensitive drug release behavior of the PEOz-PDLLA micelles. According to all the studies above, it can be concluded that the PEOz-PDLLA block copolymer micelles may be applied as promising drug delivery system for hydrophobic anti-tumor drugs.

The distribution of azidothymidine palmitate galactosylated liposomes in mice / 药学学报

Hepatocytes act as a reservoir for the human immunodeficiency viruses (HIV) and are responsible for its continual dissemination in the peripheral circulation. For this reason, galactosylated liposomes (GalLs) containing home-made [(2-lactoylamido) ethylamino] formic acid cholesterol ester (CH-ED-LA ) as a homing device were prepared to study the biodistribution of the liposomal azidothymidine palmitate (AZTP) in mice. Four liposomes of the present study, soybean phosphatidylcholine (SPC)/cholesterol(CH)/CH-ED-LA (80 : 10: 10, 10% GalLs), SPC/CH/CH-ED-LA (80 : 15:5, 5% GalLs), SPC/CH/CH-ED-LA (80 : 17 : 3, 3% GallLs) and SPC/CH (80 : 20, CL) incorporated AZTP were prepared by ethanol-injection method followed by ultrasonic-dispersion and characterized by entrapped efficiency which was more than 95% and their mean diameter was less than 100 nm, respectively. The effects of the addition upon the liposomal membrane potential and AZTP content were also unseen. The distributions of AZT in various organs were determinated by reversed phase HPLC after intravenous administration via tail vein in mice, at a dose of 15.85 mg x kg(-1) AZT solution and 30 mg x kg(-1) AZTP (at equimolar doses) in CL or GalLs, respectively. Compared to AZT control solution, the half-life of AZT in each group of AZTP liposomes increased significantly (P < 0.05). In addition, the concentration-averaged overall drug targeting efficiency (r(e)) of the liver presented by AZTP CL and GalLs containing 3% , 5% , 10% (mol/mol) CH-ED-LA increased 1.32 and 1.48, 2.13, 1.50 times as that of AZT solution, respectively. These results indicate that liposomes containing such novel galactosylated lipid, CH-ED-LA, had remarkably improved the targetability of AZTP to liver, and are anticipated to be a potential candidate for liver targeting delivery carriers.