Development of a precision tumor bone metastasis model by a magnetic micro-living-motor system.

An ideal bone metastasis animal model is critical and fundamental for mechanistic research and following development of new drug and treatment. Caudal artery (CA) injection allows bone metastasis in the hindlimb, while in-depth targeted and quantitative studies of bone metastasis require a new model to overcome its limitations. Here, we developed a targeted, quantitative, and highly consistent method for the modeling of bone metastasis with cell-based magnetic micro-living-motor (MLM) system created by effectively combining Fe3O4-PDA-Au with biosafety. The MLM system can achieve efficient migration, target site colonization and control tumorigenesis in bone precisely with the application of a magnetic field. In vivo, day 3 post cell injection, tumor bone metastasis signals were observed locally in the injected femur among 82.76% mice of the MLM group as compared to the 56.82% in the CA group, and the signal intensity was 45.1 and 95.9 times stronger than that in the left and right lower limbs of the CA group, respectively. Post-injection day 28, metastasis in vital organs was reduced by approximately 90% in the MLM group compared to the CA group. Our innovative use of the MLM system in the field of tumor modeling opens a new avenue for exploring the mechanisms of tumor bone metastasis, recurrence and drug resistance.

[Experimental research of effect of crude and processed Herba Siegesbeckiae on anti-inflammation and anti-rheumatism].

OBJECTIVE: To find out the specialities of the effect of crude and processed Herba Siegesbeckiae on anti-inflammation and anti-rheumatism. METHOD: Experiments were made on rats with swelling foot induced by carrageenin; experiments were made on mice with swelling ear induced by xylol; experiments were made on rats with chronic granuloma; experiments were made on rats with adjuvant arthritis. RESULT: Foot swelling induced by carrageenin could be diminished with crude and processed Herba Siegesbeckiae at 6.0, 2.0 g x kg(-1). The rate of inhibition of foot swelling was more than 40%, effect of the crude drug was better than that of the processed one; both of them at 6.0, 2.0 g x kg(-1) could protect rats from primary and continuous lesion of adjuvant arthritis. The effect of the processed herb was obviously better than that of the crude one in its starting minute, strength and sustaining time. CONCLUSION: The processed Herba Siegesbeckiae has obvious inhibition effect on immune inflammation. It is better than the crude Herb. Both of them have obvious inhibition effect on inflammation caused by carrageenin, with no distinct difference.