Salvatore Surdo

Band selection techniques are widely explored in spectroscopic analysis to enhance predictive performance. This study aims to inform the design of the spectral dispersion component of a low-cost smartphone microspectrometer by identifying the most informative bands within practical constraints on the number of bands and spectral range. The goal is to enable rapid, affordable, and accurate leaf Nitrogen (N) assessment as part of the DEMETRA project, which promotes methodological and technological innovation for smart nutrient estimation in agriculture. Three band selection methods were evaluated: Permutation Feature Importance (PFI), Recursive Feature Elimination (RFE), and Genetic Algorithms (GA), each integrated with machine learning regression models. Among these, GA proved most effective, outperforming models based on the full spectral range. The results highlight the potential of targeted band selection for cost-effective, in-field spectroscopic tools.

Cancer treatment, particularly chemotherapy, requires balancing efficacy and toxicity. Although traditional monitoring methods can lead to suboptimal outcomes, emerging implantable chemical sensors can complement them by providing precise, real-time drug monitoring at tumor sites, although the technology remains in its early stages. Here, we introduce an ultrathin, bioresorbable implantable biosensor for real-time doxorubicin monitoring in vivo with high spatiotemporal resolution. The sensor amplifies the drug’s fluorescence, enabling successful tracking of doxorubicin through the skin in live mice following intravenous injection. When paired with a reusable electronic patch, the biosensor facilitates seamless data collection and wireless transmission. A 3-month biocompatibility study, including systemic toxicity assessments, histological and blood analyses, confirms complete biodegradation with no observed toxicity. By directly measuring chemotherapeutic drug levels in tissues over time, our sensor enhances traditional monitoring methods, enabling clinicians to optimize dosing during cancer treatment and reduce the risk of locoregional recurrence following tumor removal.

Age-related macular degeneration (AMD) causes severe vision impairments, including blindness. An option to improve vision in AMD patients is through intraocular lenses and optics. Among others, implantable miniaturized telescopes, which direct light to healthy lateral regions of the retina, can be highly effective in improving vision in AMD patients. Yet, the quality of the restored vision might be sensitive to the optical transmission and aberrations of the telescope. To shed light on these points, we studied the in vitro optical performance of an implantable miniaturized telescope, namely, the SING IMT™ (Samsara Vision Ltd., Far Hills, NJ, USA) designed to improve vision in patients affected by late-stage AMD. Specifically, we measured the optical transmission in the spectral range 350–750 nm of the implantable telescope with a fiber-optic spectrometer. Wavefront aberrations were studied by measuring the wavefront of a laser beam after passing through the telescope and expanding the measured wavefront into a Zernike polynomial basis. Wavefront concavity indicated that the SING IMT™ behaves as a diverging lens with a focal length of −111 mm. The device exhibited even optical transmission in the whole visible spectrum and effective curvature suitable for retinal images magnification with negligible geometrical aberrations. Optical spectrometry and in vitro wavefront analysis provide evidence supporting the feasibility of miniaturized telescopes as high-quality optical elements and a favorable option for AMD visual impairment treatments.

Purpose: Evaluating the optical transmission and geometrical aberrations of an intraocular device, namely, the Small-Incision New Generation Implantable Miniature Telescope (SING IMT™, Samsara Vision), designed to correct age-related macular degeneration. Methods: Optical transmission in the spectral range 350-750 nm of the implantable optics was recorded with a fiber-optic spectrometer. Geometrical aberrations were studied by measuring the wavefront of a laser beam after passing through the implantable optics and performing an expansion of the measured wavefront into a Zernike polynomial basis. The study was conducted under in-vitro experimental conditions. A second monofocal intraocular lens (SY60WF, Alcon) was tested and used as reference for assessing the optical quality of the SING IMT™ device. Results: Spectroscopy measurements revealed that the SING IMT™ and monofocal IOL element feature UV-rejection and blue-rejection capabilities, respectively. Wavefront concavity indicated that the SING IMT™ behaves as a diverging lens with a focal length of approximately -100 mm; Zernike analysis showed that SING IMT™ has negligible coma, trefoil, astigmatism, and spherical aberrations of any order and along any direction. Conclusions: The SING IMT™ exhibited even optical transmission in the whole visible spectrum and curvature capable of magnifying the retinal images without introducing geometrical aberrations, which proves the feasibility of this device as high-quality optical element for imaging. The rigidity of the compound lens of the SING IMT™ prevents mechanically-induced distortions, an issue encountered with polymeric lenses. Translational Relevance: Spectrometry and in vitro wavefront analysis provide evidence supporting the new generation miniaturized telescopic intraocular lens as a favorable option to intraocular implant in age-related macular degeneration.

Microfluidics is revolutionizing the way research on cellular biology has been traditionally conducted. The ability to control the cell physicochemical environment by adjusting flow conditions, while performing cellular analysis at single-cell resolution and high-throughput, has made microfluidics the ideal choice to replace traditional in vitro models. However, such a revolution only truly started with the advent of polydimethylsiloxane (PDMS) as a microfluidic structural material and soft-lithography as a rapid manufacturing technology. Indeed, before the “PDMS age,” microfluidic technologies were: costly, time-consuming and, more importantly, accessible only to specialized laboratories and users. The simplicity of molding PDMS in various shapes along with its inherent properties (transparency, biocompatibility, and gas permeability) has spread the applications of innovative microfluidic devices to diverse and important biological fields and clinical studies. This review highlights how PDMS-based microfluidic systems are innovating pre-clinical biological research on cells and organs. These devices were able to cultivate different cell lines, enhance the sensitivity and diagnostic effectiveness of numerous cell-based assays by maintaining consistent chemical gradients, utilizing and detecting the smallest number of analytes while being high-throughput. This review will also assist in identifying the pitfalls in current PDMS-based microfluidic systems to facilitate breakthroughs and advancements in healthcare research.

Nanostructured surfaces and devices offer astounding possibilities for biomedical research, including cellular and molecular biology, diagnostics, and therapeutics. However, the wide implementation of these systems is currently limited by the lack of cost-effective and easy-to-use nanopatterning tools. A promising solution is to use optical methods based on photonic nanojets, namely, needle-like beams featuring a nanometric width. In this review, we survey the physics, engineering strategies, and recent implementations of photonic nanojets for high-throughput generation of arbitrary nanopatterns, along with applications in optics, electronics, mechanics, and biosensing. An outlook of the potential impact of nanopatterning technologies based on photonic nanojets in several relevant biomedical areas is also provided.

The high versatility of laser direct-write (LDW) systems offers remarkable opportunities for Industry 4.0. However, the inherent serial nature of LDW systems can seriously constrain manufacturing throughput and, consequently, the industrial scalability of this technology. Here we present a method to parallelise LDWs by using acoustically shaped laser light. We use an acousto-optofluidic (AOF) cavity to generate acoustic waves in a liquid, causing periodic modulations of its refractive index. Such an acoustically controlled optical medium diffracts the incident laser beam into multiple beamlets that, operating in parallel, result in enhanced processing throughput. In addition, the beamlets can interfere mutually, generating an intensity pattern suitable for processing an entire area with a single irradiation. By controlling the amplitude, frequency, and phase of the acoustic waves, customised patterns can be directly engraved into different materials (silicon, chromium, and epoxy) of industrial interest. The integration of the AOF technology into an LDW system, connected to a wired-network, results into a cyber-physical system (CPS) for advanced and high-throughput laser manufacturing. A proof of concept for the computational ability of the CPS is given by monitoring the fidelity between a physical laser-ablated pattern and its digital avatar. As our results demonstrate, the AOF technology can broaden the usage of lasers as machine tools for industry 4.0

Micro and nanofabrication offers remarkable opportunities for the preparation of label-free biosensors exploiting optical resonances to improve sensitivity and reduce detection limit, once specificity is imparted through surface biofunctionalization. Nonetheless, both surface roughness, peculiar of fabrication processes, and bioassay roughness, resulting from uneven molecule coverage of the sensing surfaces, produce light scattering and, in turn, deterioration of biosensing capabilities, especially in resonant cavities where light travels forth and back thousands to million times. Here we present a quantitative theoretical analysis about impact of both fabrication and bioassay surface roughness on the performance of optical biosensors exploiting silicon-based, vertical one-dimensional (1D) photonic crystal resonant cavities, taking also noise of measurement setup into account. 1D photonic crystal resonant cavities with different architectures and quality factors ranging from 102 to 106 have been considered. The analysis points out that whereas sensitivity and linearity of the biosensors are not affected by roughness level, either due to fabrication or bioassay, limit of detection can be significantly degraded by both of them, depending on quality factor of the cavity and noise level of the measurement system. The paper provides important insight into performance versus design, fabrication, and readout of biosensors based on resonant 1D photonic crystal for real-setting operation.