OBJECTIVETo establish a serum-free culture system of dendritic cells (DCs) from chronic myeloid leukemia (CML) cells so that DCs vaccine may be applied to the adoptive immunotherapy of CML in the near future.

METHODSFetal calf serum, serum-free medium and autologous serum were used for culture of DCs. The usage of cytokines was classified into two groups: group A (stem cell factor, granulocyte/macrophage colony-stimulating-factor, tumor necrosis factor-alpha and interleukin-4) and group B (granulocyte/macrophage colony-stimulating-factor, tumor necrosis factor-alpha and interleukin-4). The phenotypes of DCs were analyzed by using indirect immunofluorescence and flow cytometry. Mixed leukocyte responses were performed by methyl thiazolyl tetrazolium (MTT) assay. Chromosome analysis of DCs can be achieved by displaying G banding. T cells from CML patients were stimulated with autologous DCs and T-cell cytotoxicity was measured by (MTT) assay.

RESULTSCD34(+) cells or mononuclear cells were obtained from peripheral blood or bone marrow samples of eight patients of chronic-phase CML. Group A of serum-free medium was better than group B in expansion of total cell numbers and the rate of DCs. These results of serum-free medium were not significantly different from those of fetal calf serum medium, but the results of autologous serum medium were inferior to two groups above. The expression of major histocompatibility complex class II antigen on the surface of DCs was notable (> 50%), but the expression of CD83 and the costimulatory molecules CD86 was not noticeable (10% - 50%). Although CD1a(+)/CD14(-) DCs were potent stimulators of allogeneic lymphocytes, expansion of T cells from normal volunteers were not significant (average 27.2 fold at DCs: T cells ratio of 1:10). At day 12, CD1a(+) cells from three patients were studied by displaying G banding and Ph(+) cells in these populations were 100%, 98% and 60%, respectively. At an effector: target ratio of 40:1, 32% to 45% cytotoxicity was noted with DC-stimulated T cells against autologous leukemia cells.

CONCLUSIONSA stable serum-free culture system of CML-DCs was established. The expression of CD83 and CD86 on the surface of CML-DCs and DCs' potent stimulation of allogeneic lymphocytes were not notable. DCs in CML patients can be derived from the malignant clone and these malignant DCs could induce anti-leukemic reactivity in autologous T lymphocytes without the necessity for additional exogenous antigens.

Cells, Cultured ; Culture Media, Serum-Free ; Cytotoxicity, Immunologic ; Dendritic Cells ; physiology ; Humans ; Immunotherapy, Adoptive ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; immunology ; therapy ; T-Lymphocytes ; immunology

Objective:To standardize the bacterial endotoxin testing criteria for zoledronic acid injection and estab-lish a detection method using recombinant factor C(rFC).Methods:The gel-clot method(BET)was utilized to test 13 batches of zoledronic acid injection from national supervision and random inspection.Interference tests were conducted on zoledronic acid injections from three manufacturers at different concentrations(500,100,50,25 μg·mL-1)using rFC test kits from two manufacturers.Results:Detection was performed for the specification of 100 mL∶5 mg and other specifications according to＜0.50 EU per 1 mL and＜5.0 EU per 1 mg,respectively,and all results met the criteria.The recovery rate for 25 μg·mL-1 using rFC kits from both manufacturers ranged between 50％and 200％.Validation of rFC.Methods:Eight batches of zoledronic acid injection were validated at 25 μg·mL-1,five batches of zoledronic acid injection(100 mL∶5 mg)were validated at 0.5 EU·mL-1,and all recovery rates were between 50％and 200％.Conclusion:The bacterial endotoxin testing method for zoledronic acid injection can be established as follows:for large volume injection products with 100 mL or more,each 1 mL should contain less than 0.50 EU of endotoxin(following the Chinese Pharmacopoeia 2020,general chapter 1143).For other specifications,each 1 mg of zoledronic acid should contain less than 10.0 EU of endotoxin.The rFC test kit method for bacterial endotoxins involved diluting the sample with water for bacterial endotoxin testing to contain 25 μg of zoledronic acid per 1 mL,or performing 1∶1 dilution for large volume injections(100 mL∶5.0 mg specifi-cation),with recovery rate between 50％and 200％as per the kit instructions.

Four-dimensional (4D) printing is an emerging technology that combines science and engineering techniques. The term, "4D printing" was coined in 2013 and since then it has attracted a lot of interests due to its unique ability to have structural or functional transformations over time in response to external stimuli. The most important element of 4D printing is the responsive material. The recent progress research of hydrogels and related new technologies for 4D printing was summarized in the field of implanted medical devices at home and abroad in this paper. Then, it was pointed out the problems of responsive materials for 4D printing. Finally, it was prospected that the development of 4D printing technology in the field of implantable medical devices.
Hydrogels ; Printing, Three-Dimensional ; Prostheses and Implants