CHALLENGES
Due to the novelty of smart tattoos and its potential functions in healthcare settings, ​many aspects of its usage still haven't been entirely elucidated for safe usage and henceforth more research will be required in the next years to come. To overcome some of the current challenges and issues surrounding smart tattoos, we have proposed some solutions.
POWER SUPPLY
To avoid the problem of having to charge the monitoring device periodically and thereby impose an inconvenience on the user, optical biosensors will be used, which can continuously monitor biomarkers without interfering with the environment or requiring electrical power or charging. The nanoparticles are furthermore self-powered, fueled via biofuel cells properties. Certain components will react with biofuels within the blood, such as glucose, in order to convert stored biochemical energy from bodily fluids into electrical energy via biochemical reactions. This is dependable within our proposed time frame of use, will not affect the patient's health or require physical charging.
SENSOR ACCURACY
Our smart tattoos monitor individuals for sepsis via detecting the presence of various biomarkers of the condition. This allows the nanoparticles to work without interfering with the environment or requiring any further devices to work. Biomarkers specific for sepsis include blood acidity, C-reactive proteins, white blood cells, and procalcitonin, and lactate. By using multiple biomarkers, rather than a single one, which could be suggestive of multiple conditions, this allows a more accurate sensor and could even have potential of being more accurate than current tests. These nanoparticles can further be targeted to screen for other biomarkers, hence be targeted for the monitoring of different health conditions, though this would be applications that should be considered further down the line.
DEGRADATION KINETICS
The sensors will mainly be grafted from graphene oxide but all materials utilised are fully biodegradable and will break down naturally within the skin into materials absorbed by bodily cells. Hence there will be no effect on the patients as it degrades at the end of its 2-5 year lifetime and no known side effects in case of accidents resulting in the breaking of the implanted device.
PSYCHOLOGICAL IMPACT
One major risk with smart tattoos is the potential dependency on them that users may develop in regards of their own health status. To avoid the tattoo from giving them a false sense of security and a resulting disregard for their own health unless prompted by the tattoo biosensors, the tattoo will only be used for the tracking of chronic diseases or pre-existing serious medical conditions that could quickly become fatal if not monitored continuously. By using the tattoo as a tracking device rather than a preventative measurement, it will also avoid becoming a cause of anxiety for users or a trigger for self-fulfilling prophecies in terms of an individual's health and wellbeing.
We will work in conjunction with support groups such as those at the Macmillan Cancer Trust in order to determine which patients are best suited for the programme, undergoing a psychological evaluation before the device is implanted. Those sent home to be monitored will be made fully aware of the capabilities of the sensor and at which point they need to follow app alerts and go to hospital. All patients are allowed the freedom to decide if they wish to pursue care once alerted but this too will be discussed in psychological evaluations.
BIOCOMPATIBILITY
In the design of the smart tattoo, biocompatibility was of utmost priority. For this reason, the device was designed with materials that are immunosuppressant, as to not to trigger the body's immune system and minimise the risk of rejecting the tattoo. Here, the material used to hold the nanoparticles together as a scaffold was designed using graphene oxide, which is known to be biocompatible for humans and also holds a variety of other advantageous properties, such as electrical conductivity and high modularity.
POSSIBLE COMPLICATIONS
Little is currently known regarding the possible complications that can occur with the ongoing use of implanted smart tattoos. Current research looking into the targeted use of targeting the tattoo for the monitoring of Type 1 Diabetes is now starting clinical trials of using smart tattoos in rodents.
LONG-TERM DURABILITY
In current research, a smart tattoo injected into the skin will only last temporarily and hence would have to be replaced on a weekly or monthly basis in order to maintain accurate and reliable readings, due to quick degradation of the nanoparticles and hence the signals it may emit. While this repeated change would minimise risk of infection after implantation [Meetoo] and other long-term complications, this could become very cost-ineffective, depending on what material is used for the monitoring device. For long-term durability, we therefore propose to use a hydrogel or PGE nanoparticle hybrid coating, which will be applied in an attempt to reduce biofouling - the formation of a biofilm of microorganisms on a submerged device - which would prevent the sensors functioning and lead to degradation over time. Overall this should enable the sensor to successfully function over the target time period of 2-5 years.
DATA PRIVACY
In order to protect our patients' data, the smart tattoo will transmit electrophysiological data to a predetermined device such as a smartphone to our app (in progress). This app will track the continuous monitoring but will be password secure. In emergent cases, up to three named contacts can be alerted via the app and in crucial instances, emergency services can be called. A QR code will then be produced linked to the tracking data and sent to these contacts to scan on arrival to hospital, accessed only by these contacts.
NANOPARTICLES EXPOSURE
Despite some concerns about accidental exposure such as inhalation of these nanoparticles, we can ensure that during implantation there is no risk of such events. For the patient's safety, a medical grade mask may be worn but it is largely optional. In the case of accidental breaking of the needles used to implant the nanoparticles and inhalation, the particles are in sufficiently small quantities to pose little impact on health and we will hold full responsibility.