Microrobotics for Precision Biofilm Diagnostics and Treatment

Microrobotics in endodontics: A perspective

Microorganisms are the primary aetiological factor of apical periodontitis. The goal of endodontic treatment is to prevent and eliminate the infection by removing the microorganisms. However, microbial biofilms and the complex root canal anatomy impair the disinfection process. Effective and precise endodontic therapy could potentially be achieved using advanced multifunctional technologies that have the ability to access hard-to-reach surfaces and perform simultaneous biofilm killing, removal, and detection of microorganisms. Advances in microrobotics are providing novel therapeutic and diagnostic opportunities with high precision and efficacy to address current biofilm-related challenges in biomedicine. Concurrently, multifunctional magnetic microrobots have been developed to overcome the disinfection challenges of current approaches to disrupt, kill, and retrieve biofilms with the goal of enhancing the efficacy and precision of endodontic therapy. This article reviews the recent advances of microrobotics in healthcare and particularly advances to overcome disinfection challenges in endodontics, and provides perspectives for future research in the field.

Targeting biofilm infections in humans using small scale robotics

The eradication of drug-resistant microbial biofilms remains an unresolved global health challenge. Small-scale robotics are providing innovative therapeutic and diagnostic approaches with high precision and efficacy. These approaches are rapidly moving from proof-of-concept studies to translational biomedical applications using ex vivo, animal, and clinical models. Here, we discuss the fundamental and translational aspects of how microrobots target the infection sites to disrupt the structural and functional traits of biofilms and their antimicrobial resistance mechanisms. We emphasize current approaches of mechanochemical disruption and on-site drug delivery that are supported by in vivo models and preclinical testing, while also highlighting diagnostics potential. We also discuss clinical translation challenges and provide perspectives for development of microrobotics approaches to combat biofilm infections and biofouling in humans.

Thermosensitive hydrogel with programmed dual-octenidine release combating biofilm for the treatment of apical periodontitis

The utilization of intracanal medicaments is an indispensable procedure in root-canal treatment. However, the conventional intracanal medicaments still need improvement regarding antimicrobial efficacy and ease of clinical operation. To address the above issues, OCT/PECT@OCT + ALK composite hydrogel characterized by programming sequential release of dual antimicrobial agents has been proposed. Thanks to the self-assemble ability of amphiphilic copolymer poly(ε-caprolactone-co-1,4,8-trioxa [4.6]spiro-9-undecanone)-poly(ethylene glycol)-poly(ε-caprolactone-co-1,4,8-trioxa[4.6]spiro-9-undecanone) (PECT), dual hydrophilic and hydrophobic antimicrobial agents could be easily encapsulated in the hydrogel system and tailored for sequential drug release for a better antibiofilm effect. The hydrophilic octenidine (Octenidine dihydrochloride, OCT-HCl) is encapsulated in the hydrophilic part of hydrogel for instantaneous elevating the drug concentration through bursting release, and the hydrophobic octenidine (Octenidine, OCT) is further loaded into the PECT nanoparticles to achieve a slower and sustained-release profile. Additionally, calcium hydroxide (Ca(OH)2) was incorporated into the system and evenly dispersed among PECT nanoparticles to create an alkaline (ALK) environment, synergistically enhancing the antibiofilm effect with higher efficiency and prolonged duration. The antibiofilm effect has been demonstrated in root-canal models and apical periodontitis rats, exhibiting superior performance compared to clinically used Ca(OH)2 paste. This study demonstrates that OCT/PECT@OCT + ALK composite thermosensitive hydrogel is a potential intracanal medicament with excellent antibiofilm effect and clinical operability.

Chemical multiscale robotics for bacterial biofilm treatment

A biofilm constitutes a bacterial community encased in a sticky matrix of extracellular polymeric substances. These intricate microbial communities adhere to various host surfaces such as hard and soft tissues as well as indwelling medical devices. These microbial aggregates form a robust matrix of extracellular polymeric substances (EPSs), leading to the majority of human infections. Such infections tend to exhibit high resistance to treatment, often progressing into chronic states. The matrix of EPS protects bacteria from a hostile environment and prevents the penetration of antibacterial agents. Modern robots at nano, micro, and millimeter scales are highly attractive candidates for biomedical applications due to their diverse functionalities, such as navigating in confined spaces and targeted multitasking. In this tutorial review, we describe key milestones in the strategies developed for the removal and eradication of biofilms using robots of different sizes and shapes. It can be seen that robots at different scales are useful and effective tools for treating bacterial biofilms, thus preventing persistent infections, the loss of costly implanted medical devices, and additional costs associated with hospitalization and therapies.

Dental Medicine and Engineering Unite to Transform Oral Health Innovations

This perspective article urges the academic community to adopt a coordinated approach uniting dental medicine and engineering to support research, training, and entrepreneurship to address the unmet needs and spur oral health care innovations. We describe a new interschool institute that brings together dentists, scientists and engineers, resources, and a training program dedicated for affordable oral health care innovations, which may serve as a template for dental medicine-engineering integration.

Rational Designs of Biomaterials for Combating Oral Biofilm Infections

Oral biofilms, which are also known as dental plaque, are the culprit of a wide range of oral diseases and systemic diseases, thus contributing to serious health risks. The manner of how to achieve good control of oral biofilms has been an increasing public concern. Novel antimicrobial biomaterials with highly controllable fabrication and functionalization have been proven to be promising candidates. However, previous reviews have generally emphasized the physicochemical properties, action mode, and application effectiveness of those biomaterials, whereas insufficient attention has been given to the design rationales tailored to different infection types and application scenarios. To offer guidance for better diversification and functionalization of anti-oral-biofilm biomaterials, this review details the up-to-date design rationales in three aspects: the core strategies in combating oral biofilm, as well as the biomaterials with advanced antibiofilm capacity and multiple functions based on the improvement or combination of the abovementioned antimicrobial strategies. Thereafter, insights on the existing challenges and future improvement of biomaterial-assisted oral biofilm treatments are proposed, hoping to provide a theoretical basis and reference for the subsequent design and application of antibiofilm biomaterials.

Using SMART Magnetic Fluids and Gels for Prevention and Destruction of Bacterial Biofilms

Biofouling is a major problem in all natural and artificial settings where solid surfaces meet liquids in the presence of living microorganisms. Microbes attach to the surface and form a multidimensional slime that protects them from unfavorable environments. These structures, known as biofilms, are detrimental and very hard to remove. Here, we used SMART magnetic fluids [ferrofluids (FFs), magnetorheological fluids (MRFs), and ferrogels (FGs) containing iron oxide nano/microparticles] and magnetic fields to remove bacterial biofilms from culture tubes, glass slides, multiwell plates, flow cells, and catheters. We compared the ability of different SMART fluids to remove biofilms and found that commercially available, as well as homemade, FFs, MRFs, and FGs can successfully remove biofilm more efficiently than traditional mechanical methods, especially from textured surfaces. In tested conditions, SMARTFs reduced bacterial biofilms by five orders of magnitude. The ability to remove biofilm increased with the amount of magnetic particles; therefore, MRFs, FG, and homemade FFs with high amounts of iron oxide were the most efficient. We showed also that SMART fluid deposition can protect a surface from bacterial attachment and biofilm formation. Possible applications of these technologies are discussed.