Natália Andrýsková

Acoustic excitation provides a physical means of interrogating and modifying biological structures, yet the relationship between resonance, energy absorption and irreversible damage remains incompletely established. This narrative review connects early proposals for resonant viral inactivation with later advances in viral mechanics, cell disruption, microbubble dynamics and genetically encoded acoustic nanostructures. A unifying framework is developed around eigenfrequencies, coupling to an incident field, damping, nonlinear response and failure thresholds. Particular emphasis is placed on distinguishing measured structural resonances from frequency-dependent biological effects that arise from cavitation, heating or exposure geometry. Recent observations of single-virus vibrations and ultrasound-mediated disruption of enveloped viruses are assessed alongside oncotripsy and gas-vesicle imaging and mechanotherapy. Worked examples illustrate size-dependent frequency scales, resonance linewidths, pulse buildup, bubble oscillations and the practical limits of spectral selectivity. Detection and disruption are treated as distinct operating regimes of a coupled mechanical system rather than interchangeable evidence of a single mechanism. The most robust applications combine calibrated acoustic fields with independent mechanical measurements and clear biological endpoints. Future progress will require linking a measured mode to absorbed energy, structural failure and target-specific loss of function under realistic environmental conditions.

Magnetically powered micro- and nanorobots have emerged as remotely controlled carriers and tools for minimally invasive medicine. Their performance is governed by magnetic torque and force, low-Reynolds-number hydrodynamics, interactions with biological interfaces and the ability to localize and control devices in real time. This review links these physical principles to helical swimmers, surface rollers, flexible swimmers, magnetic assemblies and biohybrid systems. We evaluate experimental evidence for drug delivery, tumour targeting, cell transport, thrombus-related interventions and localized manipulation, carefully distinguishing benchtop demonstrations from animal studies and clinically relevant integrated systems. We further examine the coupled challenges of magnetic-field generation, navigation in blood and mucus, imaging, dose delivery, materials safety, biodegradation and retrieval. A microrobot becomes medically useful only when propulsion, localization and therapeutic function remain effective within the same physiological environment. Consequently, the most plausible early applications combine a well-defined access route, a constrained anatomical target, compatible imaging and a clear advantage over existing delivery or interventional approaches. Finally, we outline benchmarks for reproducibility, biological fate and clinical translation. Twenty-three fully worked examples connect magnetic forces and torques to locomotion, actuator requirements, localization uncertainty, feedback control and drug exposure; their hypothetical inputs and simplifying assumptions are stated explicitly to support reproducible teaching and preliminary design. In this review, “micro- and nanorobots” is an inclusive small-scale robotics term: we report the complete device dimensions and explicitly identify micrometre- and millimetre-scale platforms, even when their magnetic or functional constituents are nanoscale.

Amyloidosis is characterized by the deposition of misfolded proteins as highly stable, insoluble β-sheet-rich fibrils, posing a major therapeutic challenge due to their resistance to degradation. Insulin-derived amyloidosis at subcutaneous injection sites is a clinically significant complication in patients with diabetes, leading to impaired insulin absorption, unpredictable glycemic control, substantially increased insulin dose requirements, and localized masses (amyloidomas) that may require surgical excision when symptomatic. In this study, we evaluated sodium oleate-functionalized magnetic nanoparticles (MNs) with a hydrodynamic diameter of 50 nm with a magnetite (iron oxide—Fe₃O₄) core as a targeted physical intervention to disrupt preformed insulin amyloid fibrils. The strategy exploits localized nanoscale hyperthermia generated by MNs under a high-frequency radiofrequency (RF) field (1.65 MHz). Fibril integrity and disassembly kinetics were assessed using Thioflavin T (ThT) fluorescence assays and fluorescence microscopy. RF-activated MNs induced rapid, concentration-dependent fibril disruption; notably, at 2 mg/mL MNs, near-complete disassembly was achieved within 15 min—a timeframe compatible with clinical procedures. Neither RF nor MNs alone produced significant effects, confirming a synergistic magnetothermal mechanism. These results provide a proof of concept for a minimally invasive, externally triggered approach to clear localized insulin amyloid deposits, offering promising potential as a novel therapeutic strategy for managing injection-site amyloidosis in diabetic patients, where current options remain limited and often inadequate.