Template-based intervention in Boolean network models of biological systems

Turning Nature's own processes into design strategies for living bone implant biomanufacturing: a decade of Developmental Engineering

A decade after the term developmental engineering (DE) was coined to indicate the use of developmental processes as blueprints for the design and development of engineered living implants, a myriad of proof-of-concept studies demonstrate the potential of this approach in small animal models. This review provides an overview of DE work, focusing on applications in bone regeneration. Enabling technologies allow to quantify the distance between in vitro processes and their developmental counterpart, as well as to design strategies to reduce that distance. By embedding Nature's robust mechanisms of action in engineered constructs, predictive large animal data and subsequent positive clinical outcomes can be gradually achieved. To this end, the development of next generation biofabrication technologies should provide the necessary scale and precision for robust living bone implant biomanufacturing.

Batch Mode TD($\lambda$ ) for Controlling Partially Observable Gene Regulatory Networks

External control of gene regulatory networks (GRNs) has received much attention in recent years. The aim is to find a series of actions to apply to a gene regulation system making it avoid its diseased states. In this work, we propose a novel method for controlling partially observable GRNs combining batch mode reinforcement learning (Batch RL) and TD() algorithms. Unlike the existing studies inferring a computational model from gene expression data, and obtaining a control policy over the constructed model, our idea is to interpret the time series gene expression data as a sequence of observations that the system produced, and obtain an approximate stochastic policy directly from the gene expression data without estimation of the internal states of the partially observable environment. Thereby, we get rid of the most time consuming phases of the existing studies, inferring a model and running the model for the control. Results show that our method is able to provide control solutions for regulation systems of several thousands of genes only in seconds, whereas existing studies cannot solve control problems of even a few dozens of genes. Results also show that our approximate stochastic policies are almost as good as the policies generated by the existing studies.