Peptide-drug conjugates for tumor targeted diagnosis and treatment / 药学学报

Cancer is still one of the major diseases threatening human life and health. At present, how to achieve precise diagnosis and treatment of tumors is the biggest challenge in cancer treatment. Prodrugs use the tumor specificity of targeting molecules to deliver anticancer drugs to tumor sites, which can effectively improve drug bioavailability, therapeutic efficacy and safety, and are currently a hot spot in the research and development of anticancer drugs. The targeting molecules of prodrugs mainly include nucleic acid aptamers, polymers, antibodies, polypeptides, etc. Among them, polypeptides have the advantages of good biocompatibility, controllable degradation performance, high in vivo responsiveness, and simple and easy preparation methods, and are widely used. It is used to construct peptide-drug conjugates (PDC) prodrugs to achieve targeted therapy of tumors. In recent years, with the development of phage peptide library technology and peptide standard solid-phase synthesis technology, more and more targeted peptides have been discovered and effectively synthesized and modified, providing strong support for the development of PDC. This review briefly introduces the types and functions of functional peptides and linkers in PDC, and discusses the application of PDC in chemotherapy, immunotherapy and photodynamic therapy in tumor targeted diagnosis and treatment, and finally summarizes the difficulties faced by PDC drug development.

Icaritin and pyropheophorbide-a self-assembled nanomedicine for enhanced the efficacy of photodynamic tumor therapy by increase the cell autophagy / 药学学报

Autophagy often occurs after cells are attacked by oxidative stress, where damaged structures are phagocytic and degraded into nutrients, thereby reducing oxidative damage, promoting the survival of cancer cells and reducing the therapeutic effect of photodynamic therapy (PDT). However, excessive activation of autophagy can promote cell apoptosis. In this paper, the photosensitizer pyropheophorbide-a (Ppa) was used to produce a large amount of reactive oxygen species (ROS) to achieve the effect of killing cancer cells. At the same time, icaritin (Ica), an autophagy inducer, was used to over-activate autophagy, which transformed the protection of cancer cells into the promotion of cancer cell apoptosis, so as to improve the effect of photodynamic therapy. In this study, the interaction force between Ica and Ppa was exploited to successfully construct a self-assembled nanomedicine IP with good stability and high drug load. The synthesis method is simple, through using the drug itself as a carrier, and the loading capacity (LA) of Ica and Ppa can be increased to 83.53% and 16.45% without introducing potential biosafety risks of nanocarriers. Compared with free Ppa, self-assembled nanomedicine IP showed superior performance in cellular uptake and reactive oxygen species production. In addition, the self-assembled nanomedicine IP can reverse the protective autophagy induced by PDT by activating the autophagy of tumor cells, and facilitate apoptosis and antitumor coordination, which significantly improves the antitumor activity of PDT.

Tumor microenvironment responsive biomimetic nanoparticles for photodynamic tumor therapy / 药学学报

Inspired by the coordination effects between imidazole and metal ions in hemoglobin, biomimetic nanoparticles were constructed for photodynamic tumor therapy. The photosensitizer of protoporphyrin IX (PpIX) was modified with histidine, which could be self-assembled with Zn2+ to obtain the biomimetic nanoparticles (NPs). Under the conditions of high glutathione and low pH, the biomimetic nanoparticles could be degraded and released for enhanced photodynamic tumor therapy. The structures of NPs were characterized by dynamic light scattering (DLS), UV-visible spectrophotometer (UV-Vis), fluorescence microscope and transmission electron microscope (TEM). The reactive oxygen species (ROS) production ability of NPs was measured by singlet oxygen sensor green (SOSG) test kit. Mouse breast cancer cell lines (4T1 cells) were employed to investigate the subcellular organelle distribution and cytotoxicity of NPs. These results confirmed that NPs possessed a good dispersibility and stability with a uniform structure and particle size at 165 nm. Moreover, MTT assay and live/dead cell staining assay demonstrated that NPs could inhibit the proliferation of 4T1 cells and exhibit a good biocompatability. This research would promote the construction of intelligent biomedicine for tumor precision therapy.

Chemical constituents from the twigs and leaves of Harrisonia perforate / 药学学报

This study was performed to investigate the chemical constituents in the twigs and leaves of Harrisonia perforate. Six compounds were isolated from the 95% EtOH extract of the twigs and leaves of Harrisonia perforate by silica gel, ODS, Sephadex LH-20 column chromatographies and preparative HPLC. On the basis of chemical properties and spectra data, these compounds were identified as harriperfin E (1), kihadanin A (2), kihadanin B (3), 6α-acetoxyobacunol acetate (4), gardaubryone C (5), and β-sitosterol methyl ether (6), respectively. Compound 1 is a new chromone, and compounds 2-6 are isolated from this plant for the first time.

Chemical studies on roots of Ficus hirta / 中国中药杂志

Seventeen compounds were isolated from the 95% ethanolic extract of the root of Ficus hirta. Their structures were identified on the basis of physicochemical properties and spectral data analysis. The structures were elucidated as cyclomorusin (1), 3-O-[(6-O-E-sinapoyl)-beta-D-glucopyranosyl]-(1 --> 2)-beta-D-glucopyranoside (2), 3,5,4'-trihydroxy-6,7,3'-trimethoxyflavone (3), quercetin (4), tricin (5), acacetin (6), luteolin (7), apigenin (8), (E) -suberenol (9), meranzin hydrate (10), methyl eugenol (11), 3-methoxy-4-hydroxybenzoic acid (12), p-hydroxybenzoic acid (13), methyl chlorogenate (14), emodin (15), alpha-amyrin acetate (16), and beta-sitosterol emodin (17), respectively. Compounds 1-6, 9-15 were isolated from this plant for the first time.