Localized antimicrobial functionality in biomedical materials requires both rapid microbial suppression and sustained long-term protection, which are difficult to achieve simultaneously with conventional systems. Here, we present a dual-mode antimicrobial design strategy integrating release-based and contact-active mechanisms within a single platform. In this study, hybrid poly(vinyl alcohol) (PVA) filaments combining gentamicin sulfate (GES) as the drug-loaded phase and zinc oxide (ZnO) nanoparticles as the inorganic antimicrobial phase were developed via melt extrusion as a scalable and shapeable platform (PVA-ZnO-GES), and their key structural, mechanical, release, antimicrobial, and biological properties were comparatively evaluated against single-phase counterparts (PVA-GES and PVA-ZnO). Structural and morphological analyses confirmed successful incorporation of both phases, while the hybrid system exhibited a balanced mechanical response. Release studies showed a pronounced burst for the drug-loaded system (∼49% within 1 h), which was reduced in the hybrid (∼14.9%), with comparable cumulative release after 24 h, indicating controlled early-stage release behavior. Antimicrobial evaluation against Escherichia coli, Staphylococcus aureus, and Candida albicans revealed distinct profiles: rapid but spectrum-limited activity for the drug-loaded system and slower yet sustained activity for the inorganic system. The hybrid system integrated these complementary behaviors, achieving rapid initial inactivation and complete elimination of microbial populations maintained over 21 days. Short-term analysis (0-24 h) further revealed a biphasic inactivation profile, with an early fast phase achieving 3-log reduction within <2.5 h. Cytocompatibility studies demonstrated high cell viability, supporting the suitability of the developed filaments for biomedical applications. Overall, these findings demonstrate that hybrid PVA-ZnO-GES filaments provide a versatile platform for combining controlled drug release with sustained antimicrobial functionality for biomedical applications.

Investigations of ototoxicity using the zebrafish lateral line system have focused on the morphology of neuromast sensory hair cells using vital dyes. As a complement to this approach, we demonstrate the utility of lateral line - evoked potentials (LLEPs). The LLEPs were acquired with a modified auditory evoked potentials physiological rig, using a dipole stimulus that was presented at a rate of 50 Hz. Fish were subjected to 0.002% and 0.003% gentamicin solution. Differences in LLEP thresholds were observed in treated versus control animals. These data indicate that LLEPs are an effective physiological measure for assessing ototoxicity.

The nephrotoxicity and ototoxicity of Gentamicin have been extensively investigated; however, whether they induce hematotoxicity remains unclear. This study aimed to explore the binding of Gentamicin to adult hemoglobin (HbA) and its toxicological implications. The effect of Gentamicin on HbA oxidation was assessed by quantifying methemoglobin (MetHb) formation via a four-wavelength spectrophotometric method, and scavenger rescue assays were employed to elucidate the oxidative mechanism. Alterations in the oxygen-carrying capacity of both HbA and RBCs were evaluated through the acquisition of oxygen equilibrium curves and oxygen dissociation assays. The binding affinity between Gentamicin and HbA was determined by surface plasmon resonance (SPR). Furthermore, the influence of Gentamicin on the secondary and tertiary structures of HbA was examined by microfluidic modulation spectroscopy (MMS) and UV-visible absorption spectroscopy, respectively. Molecular docking was employed to predict the binding sites of Gentamicin on HbA. Molecular dynamics simulations verified the stability of the binding. Gentamicin promoted HbA autoxidation, elevating MetHb levels, and reduced the oxygen affinity of HbA. Gentamicin-promoted HbA autoxidation is primarily mediated by both direct heme-pocket perturbation and H2O2/iron-dependent amplification. SPR confirmed concentration-dependent specific binding between Gentamicin and HbA. MMS indicated no alteration in HbA secondary structure; however, UV-visible spectroscopy revealed that Gentamicin attenuated the Soret band, converted the oxyhemoglobin double-peak to a singlet, and generated a new band at 630 nm. Molecular docking predicted that Gentamicin binds β-chain residues via hydrogen, carbon-hydrogen, and hydrophobic interactions. This study reveals that Gentamicin exerts hematological effects in vitro. By binding to specific sites on HbA, Gentamicin affects the tertiary structure of HbA, promotes heme oxidation, ultimately increases MetHb content (oxidative damage), and decreases its oxygen-carrying capacity (functional impairment).

Dual-antibiotic loaded poly(ethylene glycol) (PEG)-based hydrogels were developed as antimicrobial wound dressings combining covalent and physical antibiotic incorporation. Hydrogels were prepared through amino-yne click conjugation of gentamicin sulfate (Gs) and thiol-yne cross-linking, followed by ciprofloxacin (CPX) loading via swelling-diffusion. The materials exhibited tunable gelation time, swelling capacity, and drug release profiles depending on thiol content. A dual-release mechanism was achieved, consisting of an initial burst release of CPX followed by a sustained, pH-responsive release of conjugated Gs through acid cleavage of β-aminoacrylate linkages. The hydrogels showed effective wide spectrum antibacterial activity against methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa, while cytotoxicity studies confirmed cytocompatibility at bactericidal concentrations. The results support the potential of these hydrogels as safe and effective dual-antibiotic wound dressings, allowing for the immediate elimination of invading bacteria after wounding (burst release), while maintaining long-term antibiotic release to minimize reinfection risk.

Multifunctional surface engineering of titanium implants that integrates osteogenic activity with localized antibacterial function is highly desirable yet remains challenging. Here, we report a nanostructured graphene oxide/mesoporous bioactive glass nanoparticle (GO/MBGN) nanocoating fabricated via electrophoretic deposition (EDP) using a chitosan-assisted strategy. An amine-functionalized mesoporous bioactive glass nanoparticle (MBGN-NH2) enables co-deposition with negatively charged GO, resulting in uniform and stable coatings with tunable nanotopography and composition. Structural and microscopic analyses confirm homogeneous incorporation of MBGN within the GO matrix while preserving the amorphous mesoporous structure, essential for ion release and drug loading. The GO/MBGN nanocoatings significantly enhance cellular responses in a composition-dependent manner. Notably, GO-10MBGN promotes improved cell spreading, focal adhesion, and proliferation of rat bone marrow-derived mesenchymal stem cells. Osteogenic differentiation is markedly upregulated, as evidenced by increased expression of alkaline phosphatase (ALP), collagen type I (COL I), and osteocalcin (OCN), attributed to combined effects of nanoscale surface features and sustained release of Ca2+ and SiO44- ions. Furthermore, gentamicin sulfate (GENT)-loaded MBGN endow controlled drug release, exhibiting an initial burst followed by sustained delivery over 6 weeks. This results in effective antibacterial activity against Staphylococcus aureus, with enhanced inhibition observed for higher MBGN content. Collectively, this work establishes that GO/MBGN nanocoatings possess both osteoinductive and antibacterial functionalities, offering a promising strategy for advanced titanium implants.

Aminoglycosides require therapeutic drug monitoring due to substantial pharmacokinetic variability across individuals. While population pharmacokinetic (popPK) models have been developed for individual drugs across age groups, and cross-drug maturation models have been explored, it is unclear whether pooling data across aminoglycosides improves predictive performance. We developed and evaluated a unified multi-aminoglycoside popPK model spanning neonates, children, and adults. De-identified data from 5659 amikacin, gentamicin, and tobramycin patients at 154 US institutions were split into training and testing datasets. Predictive performance in the test dataset was evaluated using mean percent error, normalized root mean square error (nRMSE), and clinical accuracy (trough concentrations correctly classified as below or above 1 mg/L and non-troughs within 20% of observation), and compared with selected published popPK models. To assess generalizability, the final model was refit using single-drug datasets and leave-one-subgroup-out datasets. The unified model achieved the lowest nRMSE across age groups, with absolute reductions of 0.6%-24.8%. Clinical accuracy was highest for the unified model, with a posteriori accuracy in pediatric patients of 56.4% versus 48% in the best published model. Leave-one-out refits yielded similar estimates but reduced precision, while single-drug models demonstrated substantially reduced precision, and one such model was not identifiable. This unified model improved predictive performance across drugs and age groups and demonstrated robustness to exclusion of individual drug-age group combinations. These findings support use of a unified aminoglycoside model for Bayesian model-informed precision dosing and demonstrate the advantages of pooling drugs within a class and across developmental stages.

Gentamicin (GEN) is a critical aminoglycoside antibiotic for severe gram-negative infections, yet its clinical utility is limited by dose-dependent nephrotoxicity (occurring in 10-25% of therapeutic courses) and hepatotoxicity. Nephrotoxicity arises from GEN accumulation in proximal tubular cells, triggering reactive oxygen species overproduction, lipid peroxidation, mitochondrial dysfunction, and intrinsic apoptotic pathway activation. Hepatotoxicity involves analogous oxidative and inflammatory mechanisms compromising hepatocellular integrity. At the molecular level, GEN-induced injury involves interconnected pathways: oxidative stress drives lipid peroxidation and depletes endogenous antioxidants; TLR4/NF-κB signaling amplifies pro-inflammatory cytokines (TNF-α, IL-1β, IL-6); NLRP3 inflammasome activation potentiates pyroptosis; the cytoprotective Nrf2/HO-1 pathway is suppressed; and Bax/Bcl-2/caspase-3 mediates terminal apoptotic death. This review systematically consolidates evidence on GEN's pharmacological profile, pathophysiological mechanisms of both organ toxicities, predisposing risk factors, and protective agents demonstrating preclinical efficacy. Nephroprotective and hepatoprotective compounds including polyphenols, flavonoids, alkaloids, and synthetic pharmacological agents are comprehensively summarized. Understanding these protective mechanisms may inform rational co-administration strategies; all supporting evidence is, however, preclinical, and none of these agents has yet been evaluated for the prevention of GEN-induced organ injury in patients, as illustrated through a proposed multi-target hepatorenoprotective framework. The proposed multi-target hepato-reno-protective strategy during GEN therapy is illustrated in Fig. 1.

Gentamicin, a widely used aminoglycoside antibiotic, causes severe nephrotoxicity and ototoxicity through ferroptosis-mediated mechanisms involving glutathione peroxidase 4 (GPX4), the cystine/glutamate antiporter SLC7A11, NADPH oxidase 4 (NOX4), and Prestin (SLC26A5). Ferrostatin-1, a selective ferroptosis inhibitor, demonstrates preclinical cytoprotective efficacy but lacks antimicrobial activity and carries active cardiotoxicity. We designed a novel hybrid compound by covalently conjugating a garosamine-derived aminoglycoside fragment of gentamicin C1 with ferrostatin-1 via an amide bond (-CO-NH-), yielding a pharmacophore-based fragment conjugate - not the complete gentamicin C1 trisaccharide - with molecular formula C19H31N5O4 (MW 393.48 g/mol); no antibacterial activity is claimed for this fragment. Multi-target blind molecular docking was performed against five therapeutically relevant proteins - GPX4, SLC7A11, NOX4, Caspase-3, and Prestin - using CB-Dock2. The hybrid showed higher predicted binding scores than gentamicin at four of five targets and than ferrostatin-1 at all five, though binding energy differences (0.4-1.3 kcal/mol) are semi-quantitative and should be interpreted cautiously given the differing molecular weights compared. Strongest binding was observed at Prestin (-9.6 kcal/mol) with seven hydrogen bond interactions at residues TYR16, ASP518, ASP645, THR647, SER705, ILE706, and HIS707. In silico ADMET profiling using SwissADME and ProTox-3.0 revealed Toxicity Class VI for the hybrid (LD50 = 12,800 mg/kg) versus Class V for gentamicin C1 (LD50 = 5000 mg/kg), with inactive predictions for cardiotoxicity and immunotoxicity in the hybrid, compared to active predictions for gentamicin C1. Bioavailability score improved from 0.17 to 0.55. These findings provide preliminary computational evidence supporting this hybrid scaffold as a hypothesis-generating candidate warranting experimental validation. This study is entirely computational; no synthesis or biological testing has been performed.

Urinary tract infections (UTIs) are among the most common bacterial infections worldwide and are associated with high recurrence rates and substantial morbidity. New therapeutic approaches are urgently needed, especially for recurrent UTIs (rUTIs), among which phage therapy represents a promising option. Here, we systematically evaluated the performance of six E. coli phages under urinary tract-relevant conditions and established a quantitative area-under-the-curve (AUC)-based framework for the rational selection of therapeutic phages. Phage lysis behavior was tested under oxic and anoxic conditions, revealing modulation by oxygen availability. Phages were also screened for biofilm-degrading activity, and in silico depolymerase predictions were compared with in vitro results, showing strong correlation. Phage-antibiotic interactions and refined treatment strategies were further investigated. Phages G9062, G10400, and MM02 emerged as the most promising candidates, remaining stable and active in urine under physiological pH fluctuations and exhibiting synergistic effects with gentamicin and fosfomycin, but not with the bacteriostatic nitrofurantoin. Importantly, we demonstrate that treatment sequence is a critical determinant of efficacy, with phage administration prior to antibiotic exposure consistently producing the strongest synergistic effects. These findings highlight the potential of phages as an integral component of a holistic therapeutic strategy for rUTIs.Importance Recurrent urinary tract infections (rUTIs) are a major clinical challenge characterized by repeated episodes, increasing antimicrobial resistance, and a substantial socioeconomic burden. Although bacteriophages represent a promising alternative or adjunct to antibiotics, their clinical translation has been hindered by the lack of standardized criteria for phage selection, dosing, and combination with antibiotics. This study addresses these gaps by defining key determinants of phage efficacy under conditions relevant to the urinary tract. Our findings highlight that phage performance is strongly shaped by the treatment environment and by interactions with antibiotics, and that inappropriate combinations or treatment sequences may compromise efficacy. By providing quantitative and transferable frameworks for evaluating phage effectivity, this work advances the rational development of phage-based therapies and helps bridge the gap between experimental phage research and clinically actionable treatment strategies for rUTI.

Urinary tract infections are highly prevalent diseases with a broad spectrum of clinical manifestations. This study investigates the influence of two key abiotic factors, pH and salinity, on the growth and antibiotic susceptibility of Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, and a clinical E. coli isolate obtained from a human urine sample. Growth kinetics and gentamicin susceptibility were evaluated across a pH range (4.5-11.0) and NaCl concentrations (0-1000 mM) using Luria-Bertani and Mueller-Hinton (MH) media. In parallel, real urine was analyzed, and urine-mimicking MH media were prepared by adjusting pH and salinity independently and in combination. Gentamicin susceptibility was strongly influenced by environmental conditions. Salinity pre-exposure increased E. coli and P. aeruginosa resistance from 23.0 to 19.0 mm and from 25.5 to 18.5 mm at 800 mM, respectively. Direct pH modification enhanced gentamicin activity at extreme pH (up to 34.33 mm in E. coli and 33.5 mm in P. aeruginosa). In standard MH medium, the clinical E. coli isolate exhibited a 32.5-mm inhibition zone and a gentamicin minimum inhibitory concentration (MIC) of 4 µg/mL. Under urine-mimicking conditions, the inhibition zone decreased to 22.5 mm, while the MIC increased eightfold to 32 µg/mL, indicating a marked reduction in gentamicin efficacy under physiologically relevant urinary conditions. These findings demonstrate that environmental stress profoundly influences gentamicin efficacy and suggest that this effect may involve physiological adaptations, including RpoS-mediated stress responses, membrane remodeling, and osmoprotective mechanisms previously described in the literature.

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) calls for novel antibiotic adjuvants. Carvacrol (Car), a natural monoterpene phenol derived from the essential oils of aromatic plants, exhibits membrane-active properties and has potential as an antibacterial adjuvant. Here, we found that Car markedly enhanced the bactericidal activities of Gentamicin (Gen) against MRSA. Mechanistically, Car dissipated membrane potential, inhibited respiratory chain dehydrogenase activity, and depleted intracellular ATP. Moreover, Car promoted membrane lipid peroxidation, ultimately leading to structural and functional membrane damage and bacterial death. Notably, pharmacological perturbation of respiratory and metabolic pathways further supported that this synergistic effect depends on bacterial respiratory bioenergetics. In addition, the combination showed favorable in vivo antibacterial efficacy in both Galleria mellonella and murine infection models, without apparent toxicity under the tested conditions. Collectively, these findings indicate that Car may serve as a natural antibacterial adjuvant for combination therapy against drug-resistant infections.

Objective: Nephrotoxicity is considered the most detrimental effect of gentamicin (GM). In this study, we investigated the potential effects for canagliflozin (CANA) to protect against GM-induced nephrotoxicity, besides the multiple molecular pathways underlying these effects.Methods: Four groups with six rats in each were used: control; GM (100 mg/kg, intraperitoneal injection) for 7 days; CANA + GM group: Rats were given CANA (10 mg/kg, by oral gavage) for 14 days, and GM (100 mg/kg, by IP) was co-administered with CANA in the last 7 days; and CANA group: Rats were given CANA (10 mg/Kg, by oral gavage) for 14 days.Results: Relative to GM-challenged rats, CANA ameliorated GM-induced changes in the state of oxidative stress. Also, CANA alleviated the GM-evoked reduction in the renal expression of SIRT1 and Nrf2. Furthermore, CANA decreased the renal expression of NF-ҡB and reduced p38-MAPK levels in kidneys of GM-treated animals. Simultaneously, GM-induced changes in the renal expression of miR-21 and miR-155 have been successfully amended by CANA.Conclusion: Altogether, current outcomes imply that modification of the SIRT1/Nrf2/HO-1, the p38-MAPK/NF-ҡB pathways, and microRNAs (miRNAs) play an important role adressing CANA's 'protective properties against GM nephrotoxicity.