Resistance Of Bacterial Biofilms Research Articles

A Mucous Permeable Local Delivery Strategy Based on Manganese-Enhanced Bacterial Cuproptosis-like Death for Bacterial Pneumonia Treatment.

Bacterial pneumonia is one of the most challenging global infectious diseases with high morbidity and mortality. Considering the antibiotic abuse and resistance of bacterial biofilms, a variety of metal-based materials have been developed. However, due to the high oxygen environment of the lungs, some aerobic infection bacteria have high tolerance to oxygen and ROS, and most of the metal-based materials based on ROS may not achieve good therapeutic effects. Inspired by the sensitivity of cuproptosis to aerobic respiratory cells, we designed a copper composite antibacterial nanoparticle and found that it can effectively induce cuproptosis-like death in the aerobic bacteria of the lungs. To address the challenge of in vivo application of cuproptosis, manganese dioxide was first incorporated to deplete protective glutathione, which can interact with copper and thus hinder the interaction of copper with proteins and assist in antibacterial action through immune enhancement. Cuproptosis-like death also requires a large number of copper ions. To meet this demand, we deliver positively hydrophilic modified composite nanoparticles that effectively penetrate the lung mucus layer directly to the lungs through local administration, and the copper ions are further released rapidly by the acidic environment at the infected site, which can further destroy bacterial biofilms in synergy with manganese. This drug-delivery system can effectively treat pneumonia caused by aerobic bacteria and avoid systemic toxicity that can be caused by large doses of copper.

Enhancing biofilm resistance and preserving optical translucency of 3D printed clear aligners through carboxybetaine-copolymer surface treatment

ObjectivesThis study aimed to use a carboxybetaine methacrylate (CBMA) copolymer solution to surface treat 3D printed clear aligners at different fabrication stages, to impart antifouling properties, and assess the surface treatment at various fabrication stages' impact on physico-mechanical characteristics. MethodsSurface treatments using a blend of 2-hydroxyethyl methacrylate (HEMA) and CBMA, termed CCS, were performed at various stages of 3D printed clear aligner fabrication. Experimental groups, CB1, CB2, and CB3, were determined by the stage of surface treatment during post-processing. CB1, CB2, and CB3 received treatment before post-curing, after post-curing, and after post-processing, respectively. Untreated samples served as controls. Physical and mechanical properties were assessed through tensile testing, Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and UV-Vis spectroscopy. The surface was further characterized through scanning electron microscopy and contact angle measurements. The cytotoxicity was assessed with 7-day elution and agar diffusion assays. Lastly, bacterial biofilm resistance was evaluated using confocal laser scanning microscopy. Crystal violet assay was performed using Streptococcus mutans. ResultsSurface treatment during CB1 stage exerted the most significantly unfavorable influence on properties of the 3D printed aligner resin. CB2 samples showed the maximum preservation of translucency even after 7-day aging. CB2 and CB3 phases showed enhanced hydrophilicity of sample surfaces with reduced adhesion of multispecies biofilm and S. mutans. SignificanceApplication of CCS surface treatment immediately after post-curing (CB2) can enhance the biofilm resistance of 3D printed clear aligners while maintaining high fidelity to optical translucency and constituent mechanical properties.

Preparation and Physicochemical Characterization of Hyaluronic Acid-Lysine Nanogels Containing Serratiopeptidase to Control Biofilm Formation

Remarkable resistance of bacterial biofilms to high doses of antimicrobials and antibiotics is one of their main challenges. Encapsulation of proteolytic enzymes is one of the suggested strategies to tackle this problem. In this regard, the antibacterial and anti-biofilm activity of biocompatible hyaluronic acid- Lysine nanogels containing serratiopeptidase (SRP-loaded HA-Lys nanogel) was assessed against P. aeruginosa and S. aureus strains. SRP-loaded HA-Lys nanogel was prepared using dropping method and optimized by Box-Behnken experimental design. These formulations were studied for physical characterization, release profile, stability, bioactivity, and anti-biofilm effects. The particle size, polydispersity index (PDI), and surface charge were measured by Zetasizer Nano ZS. The average particle size and zeta potential of the optimum sample were 156 nm and -14.1 mV, respectively. SRP release showed an initial burst followed by sustained release and the highest release was around 77%. Enzyme biological activity data revealed the higher efficiency of free SRP compared to SRP-loaded HA-Lys nanogel. The time-kill assay showed that both forms of SRP-loaded HA-Lys nanogel and blank HA-Lys nanogel showed significant antimicrobial activity against examined bacteria in comparison to the free enzyme. The obtained results demonstrated improved anti-biofilm efficacy and down regulation of tested biofilm genes for both SRP-loaded HA-Lys nanogel 100% and blank HA-Lys nanogel 100% compared to SRP 100%.

Strategies for combating antibiotic resistance in bacterial biofilms.

Biofilms, which are complexes of microorganisms that adhere to surfaces and secrete protective extracellular matrices, wield substantial influence across diverse domains such as medicine, industry, and environmental science. Despite ongoing challenges posed by biofilms in clinical medicine, research in this field remains dynamic and indeterminate. This article provides a contemporary assessment of biofilms and their treatment, with a focus on recent advances, to chronicle the evolving landscape of biofilm research.

Selected antimicrobial essential oils to eradicate multi-drug resistant bacterial biofilms involved in human nosocomial infections

Biofilms are the primary source of contamination linked to nosocomial infections by promoting bacterial resistance to antimicrobial agents, including disinfectants. Using essential oils, this study aims to inhibit and eradicate the biofilm of enterobacteria and staphylococci responsible for nosocomial infections at Guelma Hospital, northeastern Algeria. Thymbra capitata, Thymus pallescens and Artemesia herba-alba essential oils were evaluated against clinical strains of Klebsiella pneumoniae, Escherichia coli, and Staphylococcus aureus. The antimicrobial activity of the essential oils under consideration was assessed using an agar disc diffusion assay and the determination of minimum inhibitory concentrations (MICs). In addition, the crystal violet method and scanning electron microscopy (SEM) evaluated biofilm inhibition and eradication by those antimicrobial agents. The results indicate that T. pallescens essential oil was the most effective antimicrobial agent against pathogenic bacteria, with large zones of inhibition (up to 50 mm against S. aureus), low MICs (0.16 to 0.63 mg/mL), and powerful biofilm eradication up to 0.16 mg/mL in both 24 h and 60-min exposure times. Thus, Algerian thyme and oregano could be used in various ways to combat the biofilm that causes nosocomial infection in local hospitals.

Molecular mechanisms of biofilm resistance against antibiotics

Biofilms are immobile communities of microbes attached to biotic an abiotic surfaces and are embedded inside a self-produced cement-like extracellular polymeric substances. The resistance of biofilms against commonly used drugs has been implicated in the pathogenesis of various bacterial infections under medical and veterinary settings which normally cannot be eradicated by antibiotics. Biofilms are characterized by the ability to evade not only the antibiotic effects but also the host immune system clearance. Currently the most worrisome aspect of global human health is the rise and spread of antimicrobial resistance in bacterial pathogens and this crisis got deepened by the emergence of antimicrobial resistance of bacterial biofilms. Different antibiotic resistance mechanisms, processes by which a target pathogen curtails the interaction between an antimicrobial agent and its intended target molecules, adopted by biofilms have been discussed in this review. Different antibiotic resistance mechanisms are employed by the biofilms depending on the species of the bacteria, growth conditions, and the antibiotic involved. Commonly, the role of biofilm matrix polysaccharides, antibiotic-modifying or degrading enzymes, extracellular DNA, hypoxic conditions, presence of efflux pumps, quorum sensing, horizontal gene transfer, mutation frequency, etc. have been implicated in antibiotic resistance of biofilms. This review also discusses different approaches of overcoming biofilm infections or biofilm resistance. However, it is pertinent to mention that since no new class of antibiotics have been approved in last four decades there is the need of greater understanding of biofilm-associated antibiotic resistance to effectively utilise the therapeutic value of the existing antibiotics. Although a number of anti-biofilm strategies have been put forward as discussed in this review, they are still in nascent stage and need to undergo clinical trials to reach the commercial market.

Ecology and Evolutionary Biology of Hindering Phage Therapy: The Phage Tolerance vs. Phage Resistance of Bacterial Biofilms.

As with antibiotics, we can differentiate various acquired mechanisms of bacteria-mediated inhibition of the action of bacterial viruses (phages or bacteriophages) into ones of tolerance vs. resistance. These also, respectively, may be distinguished as physiological insensitivities (or protections) vs. resistance mutations, phenotypic resistance vs. genotypic resistance, temporary vs. more permanent mechanisms, and ecologically vs. also near-term evolutionarily motivated functions. These phenomena can result from multiple distinct molecular mechanisms, many of which for bacterial tolerance of phages are associated with bacterial biofilms (as is also the case for the bacterial tolerance of antibiotics). The resulting inhibitions are relevant from an applied perspective because of their potential to thwart phage-based treatments of bacterial infections, i.e., phage therapies, as well as their potential to interfere more generally with approaches to the phage-based biological control of bacterial biofilms. In other words, given the generally low toxicity of properly chosen therapeutic phages, it is a combination of phage tolerance and phage resistance, as displayed by targeted bacteria, that seems to represent the greatest impediments to phage therapy's success. Here I explore general concepts of bacterial tolerance of vs. bacterial resistance to phages, particularly as they may be considered in association with bacterial biofilms.

CHARACTERISTICS OF NANOMETRIC PARTICLES OF METAL OXIDES

Introduction. This mini-review examines the mechanisms of damage to bacterial biofilms (BB) by particles of metals (Au, Ag, Fe, Cu, Zn, Mg) and their oxides (AuО, SiO, Fe2О3, Ag2O, CuO, TiO2, ZnO, and MgO). Emphasis is placed on the mechanism which includes the formation of reactive oxygen species that affect the redox state of the bacterial cell and, as a result, its death. The mechanism of the antibacterial action of particles, ZnO, as well as their effect on the porosity and degree of swelling of the apatite-biopolymer composite, were considered in more detail. Due to the emergence of antibiotic resistance of bacterial biofilms, it has become increasingly difficult to treat them effectively. Materials and Methods. An analytical review of scientific publications was conducted using official databases. The scientific research method was employed to achieve the objective. Results. The study showed that nanoparticles of metal oxides could have a detrimental effect on bacterial biofilms using various mechanisms of antibacterial action, including oxidative stress, biofilm inhibition, inhibition of protein synthesis and DNA damage, damage to metabolic pathways, penetration through the cell membrane, and interaction with the cell wall and membrane. Conclusion. To further utilize nanoparticles of metal oxides (copper, gold, silver, titanium, and iron), the primary mechanisms of their influence on the structure of bacterial biofilms (BBs) were studied based on papers published in the world’s scientific literature. NPs have different classifications and differ in chemical composition and physical parameters, such as nanosize and surface-to-volume ratio.

Farm Biosecurity Measures and Interventions with an Impact on Bacterial Biofilms

Farm biosecurity management includes a set of practical measures used to prevent and limit the spread of infections to humans and animals. Infections, predominantly caused by zoonotic agents, often occur due to a lack of safety standards monitoring on farms, but also because of the use of inappropriate antimicrobial products leading to bacterial resistance, tolerance to biocides and the emergence antimicrobial-resistant germs. To date, research was mainly focused on studying the antimicrobial resistance in bacterial biofilms and the mechanisms involved in their occurrence. At molecular level, the limited diffusion of biocides in the biofilm matrix, enzyme-mediated resistance, genetic adaptation, efflux pumps, and levels of metabolic activity inside the biofilm are some of the investigated biological mechanisms which can promote antimicrobial resistance in biofilms were also investigated. Interventions, based on the identification of novel antimicrobial compounds, that would exclude the occurrence of bacterial tolerance, including essential oils (oregano, cloves), organic acids (tannic & oleic acid) and natural plant compounds (e.g. alkaloids, flavonoids, tannins and coumarins) were also extensively studied and reviewed given their effectiveness against pathogen-produced biofilms. The aim of this review was emphasize the importance of biosecurity and farm management practices and to assess their impact on bacterial biofilm formation. Furthermore, we present the recent intervention strategies aimed at reducing and combating the formation of bacterial biofilms in livestock farms.

Antimicrobial Peptides against Multidrug-Resistant Pseudomonas aeruginosa Biofilm from Cystic Fibrosis Patients

Lung infection is the leading cause of morbidity and mortality in cystic fibrosis (CF) patients and is mainly dominated by Pseudomonas aeruginosa. Treatment of CF-associated lung infections is problematic because the drugs are vulnerable to multidrug-resistant pathogens, many of which are major biofilm producers like P. aeruginosa. Antimicrobial peptides (AMPs) are essential components in all life forms and exhibit antimicrobial activity. Here we investigated a series of AMPs (d,l-K6L9), each composed of six lysines and nine leucines but differing in their sequence composed of l- and d-amino acids. The d,l-K6L9 peptides showed antimicrobial and antibiofilm activities against P. aeruginosa from CF patients. Furthermore, the data revealed that the d,l-K6L9 peptides are stable and resistant to degradation by CF sputum proteases and maintain their activity in a CF sputum environment. Additionally, the d,l-K6L9 peptides do not induce bacterial resistance. Overall, these findings should assist in the future development of alternative treatments against resistant bacterial biofilms.

A Microfluidic Chip for Studies of the Dynamics of Antibiotic Resistance Selection in Bacterial Biofilms.

Biofilms are arguably the most important mode of growth of bacteria, but how antibiotic resistance emerges and is selected in biofilms remains poorly understood. Several models to study evolution of antibiotic resistance have been developed, however, their usability varies depending on the nature of the biological question. Here, we developed and validated a microfluidic chip (Brimor) for studying the dynamics of enrichment of antibiotic-resistant bacteria in biofilms using real-time monitoring with confocal microscopy. In situ extracellular cellulose staining and physical disruption of the biomass confirmed Escherichia coli growth as biofilms in the chip. We showed that seven generations of growth occur in 16 h when biofilms were established in the growth chambers of Brimor, and that bacterial death and growth rates could be estimated under these conditions using a plasmid with a conditional replication origin. Additionally, competition experiments between antibiotic-susceptible and -resistant bacteria at sub-inhibitory concentrations demonstrated that the antibiotic ciprofloxacin selected for antibiotic resistance in bacterial biofilms at concentrations 17-fold below the minimal inhibitory concentration of susceptible planktonic bacteria. Overall, the microfluidic chip is easy to use and a relevant model for studying the dynamics of selection of antibiotic resistance in bacterial biofilms and we anticipate that the Brimor chip will facilitate basic research in this area.

SPR741, Double- or Triple-Combined With Erythromycin and Clarithromycin, Combats Drug-Resistant Klebsiella pneumoniae, Its Biofilms, and Persister Cells.

Klebsiella pneumoniae has emerged as a major clinical and public health threat owing to the increasing prevalence of healthcare-associated infections caused by multidrug-resistant or extensively drug-resistant strains. However, increasing antibiotic resistance and the absence of clinically effective antimicrobial agents make combination therapy an urgent need. This study investigated the anti-microbial activity of SPR741, a polymyxin B derivative, in combination with macrolide antibiotics (erythromycin and clarithromycin), against extensively drug-resistant and pandrug-resistant K. pneumoniae. Monotherapy, double, and triple combination therapies were performed to identify the most effective treatment combination using in vitro checkerboard, time-killing kinetics. Furthermore, we evaluated the biofilm eradication and persister cell-killing activity of these combinations using laser confocal microscopy and colony forming unit counting. In addition, a neutropenic mouse thigh infection model was used to assess the therapeutic efficacy and toxicity of the triple antibiotic combination against pandrug-resistant K. pneumoniae in vivo. Our results suggested that SPR741 combined with macrolides exhibited strong synergistic antibacterial activity against extensively drug-resistant and pandrug-resistant K. pneumoniae. These antibiotic combinations could also effectively eradicate highly resistant bacterial biofilms and persister cells in vitro and demonstrate considerable efficacy and low toxicity in vivo. In summary, our findings indicated that SPR741, in combination with macrolide antibiotics (double or triple combination), has the potential to serve as a novel treatment option against drug-resistant K. pneumoniae -related infections.

Exploring the Potential of Natural Product-Based Nanomedicine for Maintaining Oral Health.

Oral diseases pose a major threat to public health across the globe. Diseases such as dental caries, periodontitis, gingivitis, halitosis, and oral cancer affect people of all age groups. Moreover, unhealthy diet practices and the presence of comorbidities aggravate the problem even further. Traditional practices such as the use of miswak for oral hygiene and cloves for toothache have been used for a long time. The present review exhaustively explains the potential of natural products obtained from different sources for the prevention and treatment of dental diseases. Additionally, natural medicine has shown activity in preventing bacterial biofilm resistance and can be one of the major forerunners in the treatment of oral infections. However, in spite of the enormous potential, it is a less explored area due to many setbacks, such as unfavorable physicochemical and pharmacokinetic properties. Nanotechnology has led to many advances in the dental industry, with various applications ranging from maintenance to restoration. However, can nanotechnology help in enhancing the safety and efficacy of natural products? The present review discusses these issues in detail.

Effects of monochloramine on culturability, viability and persistence of Pseudomonas putida and tap water mixed bacterial community

Bacterial biofilms are able to persist in drinking water distribution systems (DWDS) even if disinfectants such as monochloramine are used to inhibit bacterial colonization and biofilm formation. While studies have determined the monochloramine concentrations required to inhibit bacterial biofilms, not much is known about how bacterial biofilms develop resistance towards monochloramine. This study covers the development of resistance to monochloramine in both single species and mixed bacterial biofilms. Through culturability tests and flow cytometry, exposing bacterial biofilms to monochloramine disinfection using a sub-lethal concentration (1.5 mg/L Cl2, experimentally determined) was sufficient to cause an increase of the monochloramine's inhibitory concentrations by as much as two times than what is initially required to inhibit biofilm growth. Through persister cultures and 16S rRNA next generation sequencing (NGS) studies, mixed bacterial biofilms experienced to monochloramine exposure resulted in more bacterial genera becoming persistent and resistant towards monochloramine. Through this study, bacterial genera that were persistent towards monochloramine were suggested to share common traits including the ability (1) to readily enter a persister or viable but non-culturable (VBNC) state and (2) to form biofilms primarily comprising proteinaceous extra-polymeric substances (EPS). Both of these traits also suggested that selected bacterial genera tended to be more persistent to monochloramine and produce EPS. This study advances our understanding of bacterial biofilm resistance towards monochloramine and showed the importance of maintaining monochloramine concentrations in DWDS to prevent the development of bacterial resistance towards monochloramine. KEY POINTS: • Monochloramine-resistant biofilm was developed after sub-lethal disinfection. • Mixed-species culture experienced monochloramine showed more persistence to monochloramine. • Ability to enter a persister/VBNC state is a common trait of persistent bacteria genera.

Synthesis and Bioactivity of Guanidinium-Functionalized Pillar[5]arene as a Biofilm Disruptor.

Due to the inherent resistance of bacterial biofilms to antibiotics and their serious threat to global public health, novel therapeutic agents and strategies to tackle biofilms are urgently needed. To this end, we designed and synthesized a novel guanidinium-functionalized pillar[5]arene (GP5) that exhibited high antibacterial potency against Gram-negative E. coli (BH101) and Gram-positive S. aureus (ATCC25904) strains. More importantly, GP5 effectively disrupted preformed E. coli biofilms by efficient penetration through biofilm barriers and subsequent destruction of biofilm-enclosed bacteria. Furthermore, host-guest complexation between GP5 and cefazolin sodium, a conventional antibiotic that otherwise shows negligible activity against biofilms, exhibited much enhanced, synergistic disruption activity against E. coli biofilms, thus providing a novel supramolecular platform to effectively disrupt biofilms.

Synthesis and Bioactivity of Guanidinium‐Functionalized Pillar[5]arene as a Biofilm Disruptor

AbstractDue to the inherent resistance of bacterial biofilms to antibiotics and their serious threat to global public health, novel therapeutic agents and strategies to tackle biofilms are urgently needed. To this end, we designed and synthesized a novel guanidinium‐functionalized pillar[5]arene (GP5) that exhibited high antibacterial potency against Gram‐negative E. coli (BH101) and Gram‐positive S. aureus (ATCC25904) strains. More importantly, GP5 effectively disrupted preformed E. coli biofilms by efficient penetration through biofilm barriers and subsequent destruction of biofilm‐enclosed bacteria. Furthermore, host–guest complexation between GP5 and cefazolin sodium, a conventional antibiotic that otherwise shows negligible activity against biofilms, exhibited much enhanced, synergistic disruption activity against E. coli biofilms, thus providing a novel supramolecular platform to effectively disrupt biofilms.

Spray-dried multidrug particles for pulmonary co-delivery of antibiotics with N-acetylcysteine and curcumin-loaded PLGA-nanoparticles

Nowadays, the resistance of bacterial biofilms towards the available antibiotics is a severe problem. Therefore, many efforts were devoted to develop new formulations using nanotechnology. We have developed an inhalable microparticle formulation using spray-drying combining multiple drugs: an antibiotic (tobramycin, ciprofloxacin or azithromycin), N-acetylcysteine (NAC), and curcumin (Cur). The use of PLGA nanoparticles (NP) also allowed incorporating curcumin to facilitate spray drying and modify the release of some compounds. The aerosolizable microparticles formulations were characterized in terms of size, morphology, and aerodynamic properties. Biocompatibility when tested on macrophage-like cells was acceptable after 20 h exposure for concentrations up to at least 32 µg/mL. Antibacterial activity of free drugs versus drugs in the multiple drug formulations was evaluated on P. aeruginosa in the same range. When co-delivered the efficacy of tobramycin was enhanced compared to the free drug for the 1 µg/mL concentration. The combinations of azithromycin and ciprofloxacin with NAC and Cur did not show an improved antibacterial activity. Bacteria-triggered cytokine release was not inhibited by free antibiotics, except for TNF-α. In contrast, the application of NAC and the addition of curcumin-loaded PLGA NPs showed a higher potential to inhibit TNF-α, IL-8, and IL-1β release. Overall, the approach described here allows simultaneous delivery of antibacterial, mucolytic, and anti-inflammatory compounds in a single inhalable formulation and may therefore pave the way for a more efficient therapy of pulmonary infections.

Ultrasmall AgNP-Impregnated Biocompatible Hydrogel with Highly Effective Biofilm Elimination Properties.

Ultrasmall silver nanoparticles (AgNPs; size < 3 nm) have attracted a great deal of interest as an alternative to commercially available antibiotics due to their ability to eliminate a wide range of microbial pathogens. However, most of these ultrasmall AgNPs are highly reactive and unstable, as well as susceptible to fast oxidation. Therefore, both the stability and toxicity remain major shortcomings for their clinical application and uptake. To circumvent these problems, we present a novel strategy to impregnate ultrasmall AgNPs into a biocompatible thermosensitive hydrogel that enables controlled release of silver alongside long-term storage stability and highly potent antibacterial activity. The advantage of this strategy lies in the combination of a homogenous dispersion of AgNPs in a hydrogel network, which serves as a sustained-release reservoir, and the unique feature of ultrasmall AgNP size, which provides an improved biofilm eradication capacity. The superior biofilm dispersion properties of the AgNP hydrogel is demonstrated in both single-species and multispecies biofilms, eradicating ∼80% of established biofilms compared to untreated controls. Notably, the effective antibacterial concentration of the formulation shows minimal toxicity to human fibroblasts and keratinocytes. These findings present a promising novel strategy for the development of AgNP hydrogels as an efficient antibacterial platform to combat resistant bacterial biofilms associated with wound infections.

Pyophage cocktail for the biocontrol of membrane fouling and its effect in aerobic microbial biofilm community during the treatment of antibiotics

Membrane bioreactor systems face an inevitable challenge that is biofouling, which not only hinders the operation of the system, but also poses an environmental and medical concern caused by the increased antibiotic resistance in bacterial biofilms. This study investigates the disruption of membrane fouling using bacteriophage cocktail (Pyophage) in an aerobic membrane bioreactor for treatment of wastewater containing high non-lethal concentration of erythromycin, tetracycline and sulfamethoxazole, while also considering the effect of the cocktail on performance. The results indicate that Pyophage cocktail contributes significantly to the decrease (45%) in transmembrane pressure while also suppressing biofilm-producing bacteria compared to the control reactors. It also reconstructed biodegradation mechanism of antibiotics especially increasing the relative abundance of gram-negative bacteria by enhancement the removal rate of erythromycin and sulfamethoxazole from the aerobic system to 99%.

Microneedle liquid injection system assisted delivery of infection responsive nanoparticles: A promising approach for enhanced site-specific delivery of carvacrol against polymicrobial biofilms-infected wounds.

Biofilms present a challenge to wound healing and are among the most feared complications through the course of wound management. Carvacrol (CAR) has manifested its antibiofilm potential against multidrug resistant bacterial biofilms. Herein, infection responsive nanoparticles (NPs) of CAR were developed (particle size: 199±8.21nm and drug load: 1.35mg/100µL) and microneedle liquid injection systems (AdminPen®) of various specifications were investigated as delivery devices to achieve the higher concentrations (in contrast to the concentrations delivered through topical hydrogel) of NPs at the target site. The results exhibited an improved biosafety and antibiofilm activity of CAR after encapsulation into the NPs. Ex vivo skin insertion and dermatokinetic studies suggested that AdminPen® 1500 was the most suitable device, as compared to AdminPen® 777 and 1200. Finally, animal studies showed that AdminPen® 1500 delivered around 8.5 times higher concentrations of CAR in the form of NPs as compared with pure CAR from topically applied hydrogel. Moreover, 50% of the delivered NPs from the AdminPen® 1500 were retained at the site of application for 72h, in contrast to the pure CAR from the hydrogel (5.2% only). Thus, AdminPen® assisted delivery of bacterial enzyme responsive NPs could be an effective approach for enhanced site-specific accumulation of CAR to potentially achieve the prolonged desired antibiofilm effect. However, further in vivo efficacy in a diseased model must now be investigated.