[Defensive characteristics of cones of Pinus armandii against seed-eating animals]. / 华山松球果对食种子动物的防御特征.

During the co-evolution with animals, plants evolved different defense strategies to resist predators and ensure their own survival and reproduction. We investigated the forging preference of nutcrackers (Nucifraga caryocatactes) for seeds in different parts of bending Pinus armandii cones in Southeast Tibet. We measured the morphological characteristics (length, width, thickness, and seed hull thickness) and the physical and chemical properties of concave and convex seeds of P. armandii (crude water, dry-matter at 70 ℃, crude fat, ash, protein and crude fiber). The results showed that there were significant differences in seed shell thickness, kernel percentage and empty shell percentage between the concave and convex seeds. The seed shell thickness of convex seeds (1.11±0.12 mm) was thicker than that of concave seeds (1.07±0.15 mm). The kernel weight percentage of convex seeds (24.0%) was smaller than that of concave seeds (25.4%). The empty shell percentage (11.2%), crude fat content (47.0%) of convex seeds were significantly lower than that of concave seeds (15.8% and 50.5%). The curving cones of P. armandii cause false hints to seed eaters, and protect high-quality seeds from being eaten as much as possible. Therefore, the curving cone is a defensive characteristics of P. armandii against seed predators.

Preparation and characteristics of lipid nanoemulsion formulations loaded with doxorubicin.

PURPOSE: Safe and effective lipid nanoemulsion (LNE) formulations for the antitumor delivery of doxorubicin is designed. METHODS: LNEs composed of medium-chain triglyceride, soybean oil, lecithin, and doxorubicin are prepared by a solvent-diffusion method in an aqueous system. The effects of lipid material composition and polyethylene glycol (PEG)ylation on the size, drug encapsulation efficiency, and stability of LNEs are investigated. Based on in-vitro cytotoxicity and cellular uptake tests of A549 (human lung carcinoma) cells, in-vivo biodistribution, antitumor activity, and cardiac toxicity are further examined using nude mouse bearing A549 tumor. RESULTS: The LNE size decreases from 126.4 ± 8.7 nm to 44.5 ± 9.3 nm with increased weight ratio of medium-chain triglyceride to soybean oil from 1:4 to 3:2, whereas the encapsulation efficiency of doxorubicin is slightly reduced from 79.2% ± 2.1% to 71.2% ± 2.9%. The PEGylation of LNE by 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[carboxy(PEG)2000] (DSPE-PEG 2000) does not significantly change the size and drug encapsulation efficiency. Three-month storage at room temperature and lyophilization process does not affect the drug encapsulation efficiency, whereas the size slightly increases to almost 100 nm. The in-vitro drug-release profiles of LNEs suggest that the present formulation can prolong drug release for 48 hours. LNEs can be internalized into tumor cells in vitro and efficiently accumulate in tumor tissues in vivo by passive targeting. Analysis results of in-vitro and in-vivo antitumor activities reveal that doxorubicin-loaded LNE exerts a therapeutic effect similar to that of the commercial Adriamycin. Moreover, the toxicity of doxorubicin, particularly its cardiac toxicity, is reduced. CONCLUSION: The present LNE formulation of doxorubicin can effectively suppress tumor growth and improve the safety of Adriamycin.