Klebsiella pneumoniae is a major cause of healthcare-associated and community-acquired infections, increasingly complicated by multidrug resistance (MDR) and carbapenem-resistant K. pneumoniae (CRKp). Phage-based approaches are attractive in such settings but rely on infrastructure and expertise, which are not widely available in low-resource laboratories. Here, we describe the isolation and preliminary characterization of two lytic K. pneumoniae phages, Zm_01 and Zm_02, from hospital sewer sludge in Lusaka, Zambia, using only routine microbiology equipment and simple adaptations of standard protocols. Clinical K. pneumoniae isolates, including MDR and carbapenem-resistant (meropenem-resistant) strains, were used for enrichment, double-agar overlay plaque assays, host-range screening and determination of efficiency of plating (EOP). Zm_01, isolated on a non-MDR but hypermucoviscous host, produced small, clear plaques and exhibited efficient plating on several MDR isolates, with EOP values higher on some MDR strains than on its original host. Zm_02, isolated on an MDR strain, formed large, clear plaques with halos, consistent with capsule-degrading activity. All work was performed without access to specialized equipment, such as a spectrophotometer, a shaker incubator or standard imaging equipment. These findings demonstrate that discovery and basic phenotypic characterization of therapeutically relevant K. pneumoniae phages are feasible in low-resource settings and provide a practical workflow that can underpin future functional and genomic studies, as well as the development of locally tailored phage-based interventions against MDR and CRKp infections.

Magnetic hyperthermia (≤45 °C) is a promising strategy for conditions requiring localized tissue disruption in sensitive anatomical regions, including ectopic pregnancy (EP), where temperature-sensitive trophoblasts can be selectively disrupted by modest heating. However, effective treatment requires nanoparticles that rapidly reach therapeutic temperatures after systemic administration while attenuating heat generation as the target temperature is approached to minimize damage to surrounding tissues. Here, cobalt-doped soft ferromagnetic iron oxide nanoparticles (Co-FIONs) were engineered to achieve this balance through classic temperature-dependent coercivity within the hyperthermia window. Coercivity decreased 2.27-fold at 45 °C, accompanied by a 1.58-fold reduction in heating rate from 1.9 to ∼1.2 °C s[-1], progressively attenuating heat generation while maintaining a high specific absorption rate (SAR) of 2907 ± 84 W g[-1] Fe. Box-Lucas analysis further demonstrated progressive temperature-dependent attenuation of heating kinetics, consistent with the combined effects of magnetic softening and thermal dissipation. Under biologically relevant conditions, Co-FIONs@PP retained a high SAR of 474 ± 56 W g[-1] Fe in 2.5% agar, demonstrating its ability to achieve therapeutically relevant magnetic hyperthermia at clinically feasible iron doses. Systemically administered Co-FIONs@PP also provided T2/T2*-weighted MRI contrast for localization of implantation sites. In pregnant mice, Co-FIONs@PP accumulated at fetoplacental units and, following two alternating magnetic field exposures, induced localized trophoblast apoptosis and selective gestational sac disruption while preserving adjacent endometrium and subsequent fertility. These findings establish Co-FIONs@PP as a promising theranostic platform for MRI visualization and localized magnetic hyperthermia, providing a foundation for minimally invasive, image-assisted treatment of EP.

Accurate needle placement in minimally invasive procedures is strongly influenced by the coupled mechanical effects of needle flexibility, tissue resistance, and bevel-tip geometry. This study presents a mechanics-based framework for analyzing multi-bevel steerable needles by integrating experimentally characterized phantom properties, analytical force estimation, and cantilever-beam deflection modeling. A 2% agar phantom was mechanically characterized through compression testing, and its nonlinear response was represented using a two-parameter Mooney-Rivlin constitutive model. The identified material parameters were subsequently combined with the measured needle geometry and bevel angles to calculate the transverse force generated during needle-phantom interaction. This calculated transverse force was then used as the loading input for an Euler-Bernoulli cantilever-beam model to predict the lateral deflection of the inserted needle. The analytical predictions were compared with independently measured needle deflections obtained from controlled insertion experiments at a maximum insertion depth of 130 mm. Fourteen single- and dual-bevel configurations were investigated. The (30 + 15)[o] dual-bevel configuration produced the largest maximum deflection, reaching approximately 16.0 mm, compared with 14.3 mm and 13.3 mm for the 15° and 30° single-bevel reference configurations, respectively. The results demonstrate that appropriate combinations of primary and secondary bevel angles can increase lateral steering capability while maintaining moderate insertion and penetration forces. The proposed framework provides a quantitative approach for relating phantom mechanical properties and needle-tip geometry to transverse force generation and needle deflection, thereby supporting the mechanics-based design of steerable needles for minimally invasive applications.

Nanoparticle-based carriers are key systems for the transport and delivery of nucleic acids in gene therapy, RNA therapeutics, and genome editing applications. The development of efficient delivery systems for CRISPR-Cas technologies requires reliable methods to evaluate nanocarrier-nucleic acid interactions, binding efficiency, and loading capacity. Agarose gel electrophoresis is commonly used to study these interactions through gel retardation assays, but results are often interpreted qualitatively based on visual inspection of DNA band migration. In this chapter, we present a quantitative approach that combines agarose gel electrophoresis with densitometric analysis of plasmid DNA (pDNA) bands to evaluate the interaction between pDNA and inorganic nanocarriers. The method relies on quantifying the fraction of free pDNA that migrates through the gel, while nanocarrier-pDNA systems remain near the loading wells. Band intensities are analyzed using ImageJ software to determine the amount of free pDNA and to estimate binding efficiency through depletion analysis. This protocol provides a simple and accessible strategy to quantify the loading of pDNA encoding CRISPR components, guide RNA constructs, or other nucleic acid cargos, facilitating the development and optimization of nanoparticle-based delivery systems for genome editing applications.

In vivo wave-based optical coherence elastography (OCE) is often constrained by short propagation distances, sparse spatial sampling, and low signal-to-noise ratios (SNRs), which degrade the wavenumber localization and phase-velocity accuracy of conventional two-dimensional fast Fourier transform (2D-FFT) analysis. Here, we introduce Multiple Signal Classification (MUSIC), which exploits signal-noise subspace orthogonality to improve wavenumber localization. Numerical simulations and agar phantom experiments compared MUSIC with 2D-FFT under impulse (0-800 Hz) and chirp (0-5000 Hz) excitation. Under sparse sampling (6 points over 2 mm), MUSIC maintained absolute mean biases below 1.5% for impulse excitation and 0.2% for chirp excitation across prescribed velocities of 2-20 m/s, whereas the 2D-FFT bias approached 20% at higher velocities. MUSIC also produced usable phase-velocity estimates at SNRs of 2:1 for impulse excitation and 1:5 for chirp excitation. Joint simulations spanning 6-121 spatial samples and 2-40 mm apertures further showed that sample number affected 2D-FFT accuracy more strongly than aperture length within the evaluated range. In dispersive Kelvin-Voigt simulations (μ 1 = 25 kPa, η = 0.1-5 Pa·s), the absolute mean phase-velocity bias of MUSIC remained below 0.4%, whereas 2D-FFT underestimated phase velocity by up to 17.7% under sparse sampling. Agar phantom experiments showed that MUSIC-derived phase velocity and fitted elastic shear modulus were less sensitive to spatial sample number, whereas viscosity estimates remained variable and model dependent. These findings support MUSIC as a promising alternative for dispersion analysis with improved effective wavenumber localization under practical OCE acquisition constraints.