Different action of nanoencapsulated meso-tetraphenylporphyrin in breast spheroid co-culture and mono-culture under microfluidic conditions

In cancer research, it is important to develop culture models which will reproduce natural environment of tumor, e.g. three-dimensional (3D) cell arrangement, cell-cell interactions, the presence of various cell types. To meet the demands, it is proposed a new microfluidic culture model based on spheroids composed of a co-culture of cancer and non-malignant mammary cells. This culture model is utilized for evaluation of photodynamic therapy (PDT) effectiveness with a nanoencapsulated photosensitizer (meso-tetraphenylporphyrin, nano-TPP). Thanks to such a model the mechanisms of breast cell response in spheroid co-culture and mono-culture could be investigated under microfluidic conditions. It is observed that the breast spheroid co-culture exhibits resistance to PDT procedures more than the spheroid mono-cultures. This effect could result from a different accumulation of nano-TPP and different ROS generation in both spheroid models: mono- and co-cultures. Summarizing, in this paper an innovative approach for the development of a 3D in vitro breast tumor model and its usage for the evaluation of PDT procedure effectiveness is presented.