Team:NDNF China/Implementation

Brief Introduction

To help these strains work beyond the laboratory in a safe, stable and traceable way, NDNF_China in iGEM 2021 presented Hidro: a hydrogel system enclosing engineered bacterial strains.

The outer layer of Hidro is a compact shell, offering both protection and containment, preventing the strains from escaping into the wild; the inner core of Hidro provides a supportive environment for them under harsh conditions, thus enabling their stable function; A genome-integrated Tracing and Control system offers tracking and specific killing of engineered strains in case of emergencies. We have experimentally demonstrated that Hidro can be implemented in diverse scenarios, such as heavy metal sensing, food-quality detection, drug secretion, etc.

In conclusion, Hidro can help engineered strains work beyond the laboratory in a safe, stable and traceable way. It has great potential to promote synthetic biology applications beyond the laboratory.

There are many scenarios where Hidro could act as a key player. Check out the Proposed Implementation of our Hidro system below:


Synthetic biology has greatly facilitated developments in biosensors, which are favored for their convenience and lower-pricing in comparison to conventional detection methods, as well as being able to be implemented across a wide range of arenas. Yet unavoidable exposure to outer environmental pressures, and lack in effective containment strategies has limited their potential. (for details of this please go to description)

The following two proposed scenarios will be used in demonstration of how Hidro is able to assist the strains in carrying out their functions.

Environment monitoring

In some extreme environments, the normal microorganisms designed for detecting the levels of heavy metals in water body would be killed. For example, among lakes polluted by petrochemical waste, the pH may be strongly acidic or alkaline, making it difficult for microorganisms to stay alive. However, protected by the hybrid hydrogel designed by our team, the microorganisms will still be able to function properly in the extreme environment: the inner core of the hydrogel is in direct contact with the microbes and can provide nutrients for growth and survival whereas the tough outer shell can prevent the insides from being damaged by the pH outside. Thus we believe Hidro is able to extend the range of detection, aiding scientists to expand the possibilities for biological testing of water.

Detection of food quality

Poisonings and illnesses incurred by intake of poor quality food have been persevering problems at a global scale, despite being preventable. We propose Hidro as means for precise, on-site and speedy detection of pathogens carried on food produces at ease. The outer shell of Hidro offers containment of the strains used in detecting (please check out our proof of concept/partnership for an example of a circuit design and evidence for the containment), while also permitting an exchange of "information" with the outer environment. If sensed, a change in color of Hidro will indicate the presence of the infectious agents.

Living medicine

Another prospective application of Hidro is in serving platforms for drug delivery.


Imagine being able to boost your health level (or cure your disease) just by sipping a cup of tea or coffee brewed by tea/coffee-bags. Hidro(s) can be put in tea/coffee-bags to safely secrete nutrients/drugs/or diet regulation molecules into the ordinary drink. With the design of our genetic circuit, Hidro is able to facilitate stable production of health-related molecules under appropriate stimulation like caffeine.

Drug Delivery in Gut

In addition to external secretion before ingestion, Hidros can also function directly in intestinal environments, bringing along three outstanding benefits. First, the secretion of medicine is controllable. Gene circuits are designed to be able to regulate the dosage by needs of patients. (see modelling for more) Second, Hidros can stay in the intestinal environment for a certain period, during which drugs may be secreted continuously. For patients who may have difficulty in taking medicine regularly, such as sufferers of Parkinson disease, Hidros can supply medication in a more convenient way. Thirdly, the medicine supplying system can be viewed as an automatic and dynamic living machine. Therefore, the cost incurred is relatively low compared to time and money involved in the conventional drug intake process. When it comes to resolving real-world problems, our product is potent in a wide range of fields involving "active drug delivery", the following two implementations will be given as an example: Hidro can assist people in controlling their weight by secretion of diet suppressing molecules; or, as mentioned above, in curing Parkinson disease by secretion of L-dopa. The full potential of using platforms such as Hidro in delivering medication is yet to emerge.