Current advances in the drug-loading preparation of poly(lactic-co-glycolic acid) microspheres / 中国组织工程研究

BACKGROUND: Existing flaws have been found in the production process of poly(lactic-co-glycolic acid) (PLGA) copolymer microspheres, which lead to residual solvent, low drug loading rate and low encapsulation efficiency of sustained-release microspheres.OBJECTIVE: To review different methods for preparing PLGA microspheres from the following aspects: basic principles, advantages/disadvantages, indications and future development. METHODS: We retrieved CNKI, PubMed and Google scholar to access the articles related to the technique process of preparing PLGA microspheres published from January 2012 to April 2017, including experiment and application research on the principles and advantages/disadvantages of the various processes. RESULTS AND CONCLUSION: To date, the main methods to prepare PLGA microspheres include single/re-emulsion solvent evaporation method, spray drying method, hydrogel template method, microfluid, coaxial electrostatic spraying, phase separation method, and supercritical fluid extraction. However, no valid evidences suggest that there is a technique that completely solves all potential problems, such as drug encapsulation and release, residual solvent and appropriate shape and size. Combination and modification of the production processes is expected to develop novel PLGA microspheres with ideal encapsulation efficiency and stable drug release.

The inhibitory effect of matrine on the growth of human colorectal cancer HT29 cells: an experimental observation / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To study the inhibitory and inductive effect of matrine (MA) on human colorectal cancer HT29 cells.</p><p><b>METHODS</b>MTT assay was used to determine the cell growth inhibitory rate in vitro . Changes of cell cycle and the apoptosis of HT29 cells before and after MA treatment were observed using flow cytometry and electron microscope.</p><p><b>RESULTS</b>MTT showed that 2-32 mg/mL MA inhibited the proliferation of HT29 cells (P < 0.05) in a dose- and time-dependent manner. Cells treated by 4, 8, and 16 mg/mL MA at G0/G1 phase were obviously higher than those in the negative control group (P < 0.05), indicating that the cell cycle was arrested at G0/G1 phase. Morphological apoptosis of HT29 cells could be seen under transmission electron microscope.</p><p><b>CONCLUSION</b>MA inhibited the proliferation of HT29 cells, and its mechanism might be associated with stagnation at G0/G1 phase and inducing apoptosis of HT29 cells.</p>