# Advances and Challenges in IoT-Based Smart Drug Delivery Systems: A Comprehensive Review
## 4 Research Survey for Exploring the Role of IoT in Revolutionising Healthcare
Another new approach for anticancer drug delivery to brain tumours with a biodegradable patch and wireless system is described in [64]. Promising results were found in mouse and large animal models, with tumour volume suppression and improved survival rates, indicating the potential for treating brain tumours in humans. The best way to treat medical conditions is with localised and controlled drug release using a wireless implant that is biodegradable and does not require surgical extraction; one such implant was studied in 2015 [65]. The system's efficacy and biocompatibility were proven through in vitro and in vivo studies. Wearable technology measures vital signs, leading to disease control. Closed-loop systems use wearables to deliver drugs for complete control. This text focuses on closed-loop systems and transdermal delivery technologies enabled by digital wearables [66]. A miniaturised dental patch system was developed [67] to monitor the microenvironment and control fluoride treatment for early prevention and management of tooth decay caused by oral biomes. The system utilises near-field communication for wireless data transmission with smart devices attached to the teeth. In a study performed in 2021 [68], researchers created a wireless, self-powered, and smart wound dressing for infection treatment and supervision. Its flexible electronics detect infestations, deliver medication, and allow for independent monitoring and treatment. This experiment shows potential for closed-loop biomedical systems. An implantable drug delivery device (SID) for neurological emergencies that integrates wirelessly with wearables monitoring EEG signals was designed [69], which, when tested in animals, showed that using the SID reduced brain damage and improved survival rates. In [70], wearable devices delivered drugs via the skin with electrical control. The drug is administered through a paper electrode with polypyrrole and sodium salicate. Using different potentials, this device controlled drug release dose and rate, making it ideal for closed-loop delivery and the detection of various illnesses. In another study [71], an electro-drug system for the GI tract with a capsule containing drugs, sensors, wireless capabilities, and motors was developed. Twenty healthy volunteers underwent two observational studies to evaluate the safety and functionality of the ingested capsule. In another study, 99 mTc was expelled remotely from the capsule and tracked by scintigraphy. The results showed that the capsule was safe and well tolerated, with successful transmission of temperature and pH data in 96.5% of cases. The 99 mTc was successfully removed remotely in 9 of 10 subjects, and its location correlated with scintigraphy based on pH. The wireless system [72] remotely powered the implanted device, controlling the dose rate with voltage and resistance adjustments. Proof-of-concept for the system's feasibility and controllability was demonstrated with liquid and solid drugs. The results showed consistent flow rates and steady dose release, even with a solid drug substitute. A new approach [73] integrated sensors with drug delivery devices using carbon ink embedded in PDMS membranes for accurate volume monitoring. The device delivers 7 L of drug solution with a 6.5% accuracy. Contemporary research has advanced multiple potential methodologies for drug delivery that encompass diverse approaches, such as wearable and disposable glucose monitoring devices, bi-hormal systems, encapsulation strategies, implantable devices exploiting micro- and nano-technologies, pliable and slender neural probes, 3D printing, frequency-controlled release, valveless micropumps, and iontophoretic drug delivery devices, which could potentially be employed for anaesthesia regulation, intravenous drips, insulin delivery, remote medical care, chronic obstructive pulmonary disease patient monitoring, etc.