Microcrater-Arrayed Chemiluminescence Cell Chip to Boost Anti-Cancer Drug Administration in Zebrafish Tumor Xenograft Model.

PURPOSE: The aim of this study was to develop a rapid and automatic drug screening platform using microcrater-arrayed (µCA) cell chips. METHODS: The µCA chip was fabricated using a laser direct writing technique. The fabrication time required for one 9 × 9 microarray wax chip was as quick as 1 min. On a nanodroplet handling platform, the chip was pre-coated with anti-cancer drugs, including cyclophosphamide, cisplatin, doxorubicin, oncovin, etoposide, and 5-fluorouracil, and their associated mixtures. Cell droplets containing 100 SK-N-DZ or MCF-7 cells were then loaded onto the chip. Cell viability was examined directly through a chemiluminescence assay on the chip using the CellTiter-Glo assay. RESULTS: The time needed for the drug screening assay was demonstrated to be less than 30 s for a total of 81 tests. The prediction of optimal drug synergy from the µCA chip was found by matching it to that of the zebrafish MCF-7 tumor xenograft model, instead of the conventional 96-well plate assay. In addition, the critical reagent volume and cell number for each µCA chip test were 200 nL and 100 cells, respectively, which were significantly lower than 100 µL and 4000 cells, which were achieved using the 96-well assay. CONCLUSION: Our study for the µCA chip platform could improve the high-throughput drug synergy screening targeting the applications of tumor cell biology.

A nanodroplet cell processing platform facilitating drug synergy evaluations for anti-cancer treatments.

Therapeutic drug synergism intervened in cancer treatments has been demonstrated to be more effective than using a single effector. However, it remains inherently challenging, with a limited cell count from tumor samples, to achieve potent personalized drug cocktails. To address the issue above, we herein present a nanodroplet cell processing platform. The platform incorporates an automatic nanodroplet dispenser with cell array ParaStamp chips, which were fabricated by a new wax stamping approach derived from laser direct writing. Such approach enables not only the on-demand de-wetting with hydrophobic wax films on substrates but also the mask-less fabrication of non-planar microstructures (i.e. no photolithography process). The ParaStamp chip was pre-occupied with anti-cancer drugs and their associate mixtures, enabling for the spatially addressable screening of optimal drug combinations simultaneously. Each droplet with a critical volume of 200 nl containing with 100 cells was utilized. Results revealed that the optimal combination reduces approximate 28-folds of conducted doses compared with single drugs. Tumor inhibition with the optimally selected drug combination was further confirmed by using PC-3 tumor-bearing mouse models. Together, the nanodroplet cell processing platform could therefore offer new opportunities to power the personalized cancer medicine at early-stage drug screening and discovery.

Facilitating tumor spheroid-based bioassays and in vitro blood vessel modeling via bioinspired self-formation microstructure devices.

Non-planar microstructure-based tissue culture devices have emerged as powerful tools to mimic in vivo physiological microenvironments in a wide range of medical applications. Here we report a spontaneous aqueous molding approach - inspired by Stenocara gracilipes beetles - to rapidly fabricate non-planar microstructure devices for facilitating tissue-based bioassays. The device fabrication is determined from the self-assembled liquid morphology, which is induced by condensation or guided by surface tension. Through experiments and modeling, we reveal that the molding mainly comprises two typical circular and striped domains, highlighting versatile applications for bioengineering. In addition, the molding characteristic is dependent on the geometry of the patterned wetting surfaces, the working volume of the liquid, and the interaction between the liquid and the substrate. The theoretical model, based on the geometry of the patterned liquid, is highly consistent with experimental data. We also demonstrate that our approach can facilitate the culturing of tumor spheroids incorporated with biomimic nano-cilia, rapid high-throughput drug screening, tumor spheroid migration assay, and in vitro modeling of blood vessels. Remarkably, the delivery of multiple concentrations of drugs and their associate mixtures (a total of 25 test spots in one device) can be carried out simultaneously within seconds. Taken together, these insights may offer new opportunities to tailor non-planar microstructures, and our proposed methodology can be applicable for the emerging needs in tumor cell biology and tissue engineering.

Anti-ageing effects of alpha-naphthoflavone on normal and UVB-irradiated human skin fibroblasts.

Ageing is a complex and multifactorial process resulting in several functional and aesthetic changes to the skin. We found that α-Naphthoflavone (α-NF) concentration-dependently induced pro-collagen type I protein expression and inhibited MMP-1 protein expression, in both normal and UVB-irradiated cells. SB431542 and SIS3 - inhibitors of TGF-ß and Smad3, respectively - significantly alleviate α-NF-caused response of MMP-1 and pro-collagen. LY294002 (PI3K inhibitor) can reverse α-NF-induced ERK, Akt, Smad-3 activation, pro-collagen synthesis and α-NF-suppressed AP-1 activation. PD (ERK inhibitor) was not involved in pro-collagen generation and MMP-1 inhibition. We concluded that α-NF promotes pro-collagen production and inhibits MMP-1 expression via the activation of a PI3K/Akt/Smad-3 pathway in normal and UVB-irradiated human skin fibroblasts, while TGF-ß may play an important role in transducing this pathway. These results suggest that α-NF, a natural plant product, has the potential to become a novel anti-ageing skin application.