Synthesis，Characterization and Anti-tumor Effect Evaluation of Novel Ampelopsin Derivative Poly （γ-glutamic Acid）-ampelopsin Conjugate / 中国药房

OBJECTIVE：To desig n and sy nthesize poly （γ-glutamic acid ）-ampelopsin（γ-PGA-AMP），and to characterize it and evaluate its anti-tumor activity in vitro . METHODS ：Synthetic product was produced through an esterification reaction between γ-PGA and ampelopsin. The structure of synthetic product was characterized by the UV spectrophotometry ，Fourier transform infrared（FT-IR）spectroscopy，1H-NMR spectra and the quantitative elemental analysis. The content of ampelopsin in synthetic product was determined by UV absorption spectrometry at 292 nm. Using 5-FU as positive control ，MTT assay was used to determine inhibitory effects of γ-PGA-AMP and ampelopsin on human breast cancer cell MCF- 7，human liver cancer cell HepG 2 and human lung cancer cell A 549. The IC 50 was calculated. RESULTS ：The results showed that the free 7-hydroxyl group of ampelopsin and the a-carboxyl group of γ-polyglutamic acid had been esterified to obtain γ-PGA-AMP；the yield of γ-PGA-AMP was 55.7％，and the content of ampelopsin was 32.3％. The inhibitory effect of γ-PGA-AMP and ampelopsin on MCF- 7，HepG2 and A 549 cells was obvious. IC 50 of γ-PGA-AMP（to 3 above tumor cells ）were 40.19，28.29 and 55.23 μg/mL，those of ampelopsin were 105.30，81.23，130.10 μg/mL，those of 5-FU were 24.72，87.98，30.99 μg/mL，respectively. CONCLUSIONS ：γ-PGA-AMP with anti-tumor effect in vitro is synthesized successfully ，and its anti-tumor effect is stronger than that of ampelopsin.

Safety and photochemotherapeutic application of poly(-glutamic acid)-based biopolymeric nanoparticle

The safety of nanomaterials, a crucial consideration for clinical translation, is enhanced by using building blocks that are biologically nontoxic. Here, we used poly(-glutamic acid) (-PGA) and dopamine as building blocks of polymeric nanomaterials for carrying hydrophobic anticancer drugs. The introduction of phenylalanine onto -PGA enabled the resulting amphiphilic derivative of -PGA acid to self-assemble in the presence of the anticancer drug paclitaxel (PTX) to form PTX-encapsulated micelles. The surfaces of PTX-loaded micelles were then coated with polymerized dopamine (PDA). The PDA-coated, amphiphilic -PGA-based micelles (AM) carrying PTX (PDA/AM/P) exerted near-infrared-responsive photothermal effects. Near-infrared irradiation of cancer cells treated with PDA/AM/P nanoparticles produced a greater anticancer effect than that observed in other treatment groups, indicating a synergistic effect. Intravenous administration of PDA/AM/P completely ablated tumors and prevented their recurrence. Notably, the safety profile of PDA/AM/P nanoparticles allowed PTX to be delivered at a 3.6-fold higher dose than was possible with PTX solubilized in surfactant, and circumvented the side effects of the surfactant. These results support the multifunctional potential of PDA/AM for the delivery of various hydrophobic drugs and imaging dyes for safe translation of nanomaterials into the clinic.

Regulation of Allergic Immune Responses by Microbial Metabolites

Emerging evidence demonstrates that the microbiota plays an essential role in shaping the development and function of host immune responses. A variety of environmental stimuli, including foods and commensals, are recognized by the host through the epithelium, acting as a physical barrier. Two allergic diseases, atopic dermatitis and food allergy, are closely linked to the microbiota, because inflammatory responses occur on the epidermal border. The microbiota generates metabolites such as short-chain fatty acids and poly-γ-glutamic acid (γPGA), which can modulate host immune responses. Here, we review how microbial metabolites can regulate allergic immune responses. Furthermore, we focus on the effect of γPGA on allergic T helper (Th) 2 responses and its therapeutic application.

Increased humoral antibody response of foot-and-mouth disease virus vaccine in growing pigs pre-treated with poly-γ-glutamic acid

This study was conducted to determine if humoral antibody response of foot-and-mouth disease (FMD) vaccine improved in 8-week-old growing pigs born to well-vaccinated sows pre-treated with 60 mg of poly-γ-glutamic acid (γ-PGA) three days before vaccination. Antibody against FMD virus serotype O was measured 0, 2, 4 and 6 weeks post-vaccination, using a PrioCHECK FMDV type O ELISA kit. The results showed that positive antibody reactions against FMDV serotype O antigen among a component of the vaccine significantly increased in response to pre-injection with γ-PGA.