Enhanced Eradication of Mucin-Embedded Bacterial Biofilm by Locally Delivered Antibiotics in Functionalized Microcontainers

Near-Infrared Light-Driven Mesoporous SiO2 /Au Nanomotors for Eradication of Pseudomonas aeruginosa Biofilm

Bacterial biofilms are linked to several diseases and cause resistant and chronic infections in immune-compromised patients. Nanomotors comprise a new field of research showing a great promise within biomedicine but pose challenges in terms of biocompatibility. Nanomotors propelled by thermophoresis could overcome this challenge, as they leave no waste product during propulsion. In this study, mesoporous-silica nanoparticles are coated with a thin layer of gold to make nanomotors, which can be driven by near-infrared (NIR) light irradiation. The prepared mesoporous SiO₂ -Au nanomotors exhibit efficient self-propulsion when exposed to NIR irradiation, they penetrate deep through a biofilm matrix, and disperse the biofilm in situ due to the photothermal effect on the Au part of the nanomotors. The velocities of such nanomotors are investigated at different wavelengths and laser powers. Furthermore, the study examines the ability of these nanomotors to eradicate Pseudomonas aeruginosa (P. aeruginosa) biofilm under NIR light irradiation. The conducted study shows that the nanomotor's velocity increases with increasing laser power. The mesoporous SiO₂ /Au nanomotors show excellent capabilities to eradicate P. aeruginosa biofilms even under short (30 s-3 min) irradiation time. This study shows great promise for overcoming the challenges related to bacterial biofilm eradication.

Bioadhesive Tannic-Acid-Functionalized Zein Coating Achieves Engineered Colonic Delivery of IBD Therapeutics via Reservoir Microdevices

The biggest challenge in oral delivery of anti-inflammatory drugs such as 5-aminosalicylic acid (5-ASA) is to (i) prevent rapid absorption in the small intestine and (ii) achieve localized release at the site of inflammation in the lower gut, i.e., the colon. Here, we present an advanced biopolymeric coating comprising of tannic-acid-functionalized zein protein to provide a sustained, colon-targeted release profile for 5-ASA and enhance the mucoadhesion of the dosage form via a mussel-inspired mechanism. To enable localized delivery and provide high local concentration, 5-ASA is loaded into the microfabricated drug carriers (microcontainers) and sealed with the developed coating. The functionality and drug release profile of the coating are characterized and optimized in vitro, showing great tunability, scalability, and stability toward proteases. Further, ex vivo experiments demonstrate that the tannic acid functionalization can significantly enhance the mucoadhesion of the coating, which is followed up by in vivo investigations on the intestinal retention, and pharmacokinetic evaluation of the 5-ASA delivery system. Results indicate that the developed coating can provide prolonged colonic delivery of 5-ASA. Therefore, the here-developed biodegradable coating can be an eco-friendly substitute to the state-of-the-art commercial counterparts for targeted delivery of 5-ASA and other small molecule drugs.

Sensing technologies and experimental platforms for the characterization of advanced oral drug delivery systems

Complex and miniaturized oral drug delivery systems are being developed rapidly for targeted, controlled drug release and improved bioavailability. Standard analytical techniques are widely used to characterize i) drug carrier and active pharmaceutical ingredients before loading into a delivery device (to ensure the solid form), and ii) the entire drug delivery system during the development process. However, in light of the complexity and the size of some of these systems, standard techniques as well as novel sensing technologies and experimental platforms need to be used in tandem. These technologies and platforms are discussed in this review, with a special focus on passive delivery systems in size range from a few 100 µm to a few mm. Challenges associated with characterizing these systems and evaluating their effect on oral drug delivery in the preclinical phase are also discussed.