Hard polymeric porous microneedles on stretchable substrate for transdermal drug delivery.

Microneedles offer a convenient transdermal delivery route with potential for long term sustained release of drugs. However current microneedle technologies may not have the mechanical properties for reliable and stable penetration (e.g. hydrogel microneedles). Moreover, it is also challenging to realize microneedle arrays with large size and high flexibility. There is also an inherent upper limit to the amount and kind of drugs that can be loaded in the microneedles. In this paper, we present a new class of polymeric porous microneedles made from biocompatible and photo-curable resin that address these challenges. The microneedles are unique in their ability to load solid drug formulation in concentrated form. We demonstrate the loading and release of solid formulation of anesthetic and non-steroidal anti-inflammatory drugs, namely Lidocaine and Ibuprofen. Paper also demonstrates realization of large area (6 × 20 cm2) flexible and stretchable microneedle patches capable of drug delivery on any body part. Penetration studies were performed in an ex vivo porcine model supplemented through rigorous compression tests to ensure the robustness and rigidity of the microneedles. Detailed release profiles of the microneedle patches were shown in an in vitro skin model. Results show promise for large area transdermal delivery of solid drug formulations using these porous microneedles.

Hair shaft miniaturization causes stem cell depletion through mechanosensory signals mediated by a Piezo1-calcium-TNF-α axis.

In aging, androgenic alopecia, and genetic hypotrichosis disorders, hair shaft miniaturization is often associated with hair follicle stem cell (HFSC) loss. However, the mechanism causing this stem cell depletion in vivo remains elusive. Here we show that hair shaft loss or a reduction in diameter shrinks the physical niche size, which results in mechanical compression of HFSCs and their apoptotic loss. Mechanistically, cell compression activates the mechanosensitive channel Piezo1, which triggers calcium influx. This confers tumor necrosis factor alpha (TNF-α) sensitivity in a hair-cycle-dependent manner in otherwise resistant HFSCs and induces ectopic apoptosis. Persistent hair shaft miniaturization during aging and genetic hypotrichosis disorders causes long-term HFSC loss by inducing continuous ectopic apoptosis through Piezo1. Our results identify an unconventional role of the inert hair shaft structure as a functional niche component governing HFSC survival and reveal a mechanosensory axis that regulates physical-niche-atrophy-induced stem cell depletion in vivo.

From brown to colored: Polylactic acid composite with micro/nano-structured white spent coffee grounds for three-dimensional printing.

Functional fillers in three-dimensional (3D) printing composite filaments offer an innovative way spent coffee grounds (SCGs) can be reused. However, the inherent brownness of SCGs places a limit on the color in which the composite filament and, consequently, the finished print appears. Herein, colored composite filaments for fused deposition modeling were successfully fabricated, where micro/nano-structured decolorized SCGs (MN-DSCGs) were embedded within polylactic acid (PLA) matrix. At the optimum condition, the 3D prints using composite filaments exhibit comparable tensile and flexural strength to the PLA counterparts. Also, they demonstrate superior melt flow and excellent print quality. Under the same condition, 3D printed MN-DSCGs/PLA blend has sufficient color restoration as compared to the prints using virgin PLA.

Successful In vivo Calcium Imaging with a Head-Mount Miniaturized Microscope in the Amygdala of Freely Behaving Mouse.

In vivo real-time monitoring of neuronal activities in freely moving animals is one of key approaches to link neuronal activity to behavior. For this purpose, an in vivo imaging technique that detects calcium transients in neurons using genetically encoded calcium indicators (GECIs), a miniaturized fluorescence microscope, and a gradient refractive index (GRIN) lens has been developed and successfully applied to many brain structures1 , 2 , 3 , 4 , 5 , 6. This imaging technique is particularly powerful because it enables chronic simultaneous imaging of genetically defined cell populations for a long-term period up to several weeks. Although useful, this imaging technique has not been easily applied to brain structures that locate deep within the brain such as amygdala, an essential brain structure for emotional processing and associative fear memory7. There are several factors that make it difficult to apply the imaging technique to the amygdala. For instance, motion artifacts usually occur more frequently during the imaging conducted in the deeper brain regions because a head-mount microscope implanted deep in the brain is relatively unstable. Another problem is that the lateral ventricle is positioned close to the implanted GRIN lens and its movement during respiration may cause highly irregular motion artifacts that cannot be easily corrected, which makes it difficult to form a stable imaging view. Furthermore, because cells in the amygdala are usually quiet at a resting or anesthetized state, it is hard to find and focus the target cells expressing GECI in the amygdala during baseplating procedure for later imaging. This protocol provides a helpful guideline for how to efficiently target cells expressing GECI in the amygdala with head-mount miniaturized microscope for successful in vivo calcium imaging in such a deeper brain region. It is noted that this protocol is based on a particular system (e.g., Inscopix) but not restricted to it.

A robust and miniaturized screening platform to study natural products affecting metabolism and survival in Caenorhabditis elegans.

In this study a robust, whole organism screening based on Caenorhabditis elegans is presented for the discovery of natural products (NP) with beneficial effects against obesity and age-related diseases. Several parameters of the elaborated workflow were optimized to be adapted for probing multicomponent mixtures combining knowledge from traditional medicine and NP chemistry by generating optimized small-scale extracts considering scarcity of the natural source, solubility issues, and potential assay interferences. The established miniaturized assay protocol allows for in vivo probing of small amounts of even complex samples (~ 1 mg) to test their ability to increase the nematodes' survival time and the suppression of fat accumulation assessed by Nile red staining as hall marks of "healthy aging". The workflow was applied on 24 herbal and fungal materials traditionally used against symptoms of the metabolic syndrome and revealed promising results for the extracts of Gardenia jasminoides fruits and the sclerotia from Inonotus obliquus. Tested at 100 µg/mL they were able to significantly reduce the Nile red fluorescence and extend the 50% survival rate (DT50) compared to the control groups. This phenotype-directed in vivo approach opens up new horizons for the selection of natural starting materials and the investigation of their active principles as fast drug discovery tool with predictive value for human diseases.

Challenges for Microelectronics in Non-Invasive Medical Diagnostics.

Microelectronics is emerging, sometimes with changing fortunes, as a key enabling technology in diagnostics. This paper reviews some recent results and technical challenges which still need to be addressed in terms of the design of CMOS analog application specific integrated circuits (ASICs) and their integration in the surrounding systems, in order to consolidate this technological paradigm. Open issues are discussed from two, apparently distant but complementary, points of view: micro-analytical devices, combining microfluidics with affinity bio-sensing, and gamma cameras for simultaneous multi-modal imaging, namely scintigraphy and magnetic resonance imaging (MRI). The role of integrated circuits is central in both application domains. In portable analytical platforms, ASICs offer miniaturization and tackle the noise/power dissipation trade-off. The integration of CMOS chips with microfluidics poses multiple open technological issues. In multi-modal imaging, now that the compatibility of the acquisition chains (thousands of Silicon Photo-Multipliers channels) of gamma detectors with Tesla-level magnetic fields has been demonstrated, other development directions, enabled by microelectronics, can be envisioned in particular for single-photon emission tomography (SPECT): a faster and simplified operation, for instance, to allow transportable applications (bed-side) and hardware pre-processing that reduces the number of output signals and the image reconstruction time.

Miniaturization optimized weapon killing power during the social stress of late pre-contact North America (AD 600-1600).

Before Europeans arrived to Eastern North America, prehistoric, indigenous peoples experienced a number of changes that culminated in the development of sedentary, maize agricultural lifeways of varying complexity. Inherent to these lifeways were several triggers of social stress including population nucleation and increase, intergroup conflict (warfare), and increased territoriality. Here, we examine whether this period of social stress co-varied with deadlier weaponry, specifically, the design of the most commonly found prehistoric archery component in late pre-contact North America: triangular stone arrow tips (TSAT). The examination of modern metal or carbon projectiles, arrows, and arrowheads has demonstrated that smaller arrow tips penetrate deeper into a target than do larger ones. We first experimentally confirm that this relationship applies to arrow tips made from stone hafted onto shafts made from wood. We then statistically assess a large sample (n = 742) of late pre-contact TSAT and show that these specimens are extraordinarily small. Thus, by miniaturizing their arrow tips, prehistoric people in Eastern North America optimized their projectile weaponry for maximum penetration and killing power in warfare and hunting. Finally, we verify that these functional advantages were selected across environmental and cultural boundaries. Thus, while we cannot and should not rule out stochastic, production economizing, or non-adaptive cultural processes as an explanation for TSAT, overall our results are consistent with the hypothesis that broad, socially stressful demographic changes in late pre-contact Eastern North America resulted in the miniaturization-and augmented lethality-of stone tools across the region.

Wireless, battery-free, fully implantable multimodal and multisite pacemakers for applications in small animal models.

Small animals support a wide range of pathological phenotypes and genotypes as versatile, affordable models for pathogenesis of cardiovascular diseases and for exploration of strategies in electrotherapy, gene therapy, and optogenetics. Pacing tools in such contexts are currently limited to tethered embodiments that constrain animal behaviors and experimental designs. Here, we introduce a highly miniaturized wireless energy-harvesting and digital communication electronics for thin, miniaturized pacing platforms weighing 110 mg with capabilities for subdermal implantation and tolerance to over 200,000 multiaxial cycles of strain without degradation in electrical or optical performance. Multimodal and multisite pacing in ex vivo and in vivo studies over many days demonstrate chronic stability and excellent biocompatibility. Optogenetic stimulation of cardiac cycles with in-animal control and induction of heart failure through chronic pacing serve as examples of modes of operation relevant to fundamental and applied cardiovascular research and biomedical technology.

Wearable SiPM-Based NIRS Interface Integrated With Pulsed Laser Source.

We present the design of a miniaturized probe integrating silicon photomultiplier and light-pulsing electronics in a single 2 × 2 mm2 complementary metal-oxide-semiconductor (CMOS) chip which includes functional blocks such as a fast pulse-laser driver and synchronized single-photon detection circuit. The photon pulses can be either counted on-chip or processed by an external high-speed electronic module such as time-corelated single photon counting (TCSPC) unit. The integrated circuit was assembled on a printed circuit board (PCB) and also on a 2.5D silicon interposer platform of size 1 cm and interfaced with a silicon photomultiplier (SiPM), vertical cavity surface emitting laser (VCSEL) and other ancillary components such as capacitors and resistors. Our approach of integrating an optical interface to optimize light collection on the small active area and light emission from the vertical-cavity surface-emitting laser (VSCEL) will facilitate clinical adoption in many applications and change the landscape of Near Infrared Spectroscopy (NIRS) hardware commercially due to significant optode-size reduction and the elimination of optical fibers.

Fabrication and characterization of polyimide-based 'smooth' titanium nitride microelectrode arrays for neural stimulation and recording.

OBJECTIVE: As electrodes are required to interact with sub-millimeter neural structures, innovative microfabrication processes are required to enable fabrication of microdevices involved in such stimulation and/or recording. This requires the development of highly integrated and miniaturized systems, comprising die-integration-compatible technology and flexible microelectrodes. To elicit selective stimulation and recordings of sub-neural structures, such microfabrication process flow can beneficiate from the integration of titanium nitride (TiN) microelectrodes onto a polyimide substrate. Finally, assembling onto cuffs is required, as well as electrode characterization. APPROACH: Flexible TiN microelectrode array integration and miniaturization was achieved through microfabrication technology based on microelectromechanical systems (MEMS) and complementary metal-oxide semiconductor processing techniques and materials. They are highly reproducible processes, granting extreme control over the feature size and shape, as well as enabling the integration of on-chip electronics. This design is intended to enhance the integration of future electronic modules, with high gains on device miniaturization. MAIN RESULTS: (a) Fabrication of two electrode designs, (1) 2 mm long array with 14 TiN square-shaped microelectrodes (80 × 80 µm2), and (2) an electrode array with 2 mm × 80 µm contacts. The average impedances at 1 kHz were 59 and 5.5 kΩ, respectively, for the smaller and larger contacts. Both designs were patterned on a flexible substrate and directly interconnected with a silicon chip. (b) Integration of flexible microelectrode array onto a cuff electrode designed for acute stimulation of the sub-millimeter nerves. (c) The TiN electrodes exhibited capacitive charge transfer, a water window of -0.6 V to 0.8 V, and a maximum charge injection capacity of 154 ± 16 µC cm-2. SIGNIFICANCE: We present the concept, fabrication and characterization of composite and flexible cuff electrodes, compatible with post-processing and MEMS packaging technologies, which allow for compact integration with control, readout and RF electronics. The fabricated TiN microelectrodes were electrochemically characterized and exhibited a comparable performance to other state-of-the-art electrodes for neural stimulation and recording. Therefore, the presented TiN-on-polyimide microelectrodes, released from silicon wafers, are a promising solution for neural interfaces targeted at sub-millimeter nerves, which may benefit from future upgrades with die-electronic modules.

Nephrotoxicity: Topical issue.

Drug-induced kidney injury is one of the most significant adverse events and dose limiting factor in chemotherapy as well a major cause of prospective drug attrition during pharmaceutical development. Moreover, kidney injury can also occur as a consequence of exposures to environmental xenobiotics such as heavy metals, fungal toxins and nanomaterials. The lack of adequate in vitro human kidney models that mimic more realistically the in vivo conditions and the absence of suitable and robust, cost-effective and predictive cell-based in vitro assays contribute to an underestimation of the kidney toxic potential of new drugs and xenobiotics. Therefore, a rapid screening system capable to detect potential nephrotoxicity at early stages of drug discovery is an urgent need. Here we provide an overview of human cell lines currently used as a surrogate in vitro kidney models in nephrotoxicity studies, including their advantages and limitations. In addition, the capacity of the single cell gel electrophoresis (SCGE)/comet assay as a potential tool in kidney toxicants screening is discussed. Despite a limited number of studies using the comet assay to evaluate the drug-induced kidney damage potential, a considerable variability in SCGE methodology (e.g. lysis, unwinding, and electrophoresis conditions) has been observed. Before the comet assay can be included in nephrotoxicity testing, a basic guideline has to be developed. To test its feasibility, additional in vitro experiments including inter-laboratory validation studies based on this guideline have to be performed.

Analysis of Artemisia annua extracts and related products by high performance liquid chromatography-tandem mass spectrometry coupled to sample treatment miniaturisation.

Artemisinin, the main antimalarial compound of Artemisia annua L., is currently attracting increasing interest for its antiproliferative properties, but its content is highly variable, depending on several genetic, environmental and processing conditions. Aim of the present study is to analyse the artemisinin content in different plant extracts, to test their in vitro activity on cell proliferation and then to correlate these data to the active principle concentration. For this purpose, an innovative miniaturised sample pretreatment strategy based on microextraction by packed sorbent (MEPS) was developed and coupled to an original advanced method based on liquid chromatography with diode array detection and tandem mass spectrometry (LC-DAD-MS/MS). The method was fully validated, granting consistent data. Good linearity was found over a suitable concentration range, i.e. 5-1000ng/mL. Extraction yields (>85%), precision (RSD < 3.5%) and accuracy (recovery 88-93%) were all within acceptable levels of confidence. After validation, the method was successfully applied to the determination of artemisinin in A. annua extracts. Analyte content was widely variable (up to twenty-fold) according to the starting material and the extraction procedure, ranging between 5.9µg/g and 109µg/mL. The cytotoxic activity of all analysed extracts was also tested on human leukemic cells by viable cell count and cell cycle analysis. Artemisinin concentrations and biological activity were carefully evaluated and the observed antiproliferative effects varied according to artemisinin content in each extract type. This highlights the need to quantitatively analyse the main active constituent of plant extracts and the obtained data have shown to be promising for the choice of the related herbal product dosage.

Real-world comparison of in-hospital Reveal LINQ insertable cardiac monitor insertion inside and outside of the cardiac catheterization or electrophysiology laboratory.

BACKGROUND: Traditionally, insertable cardiac monitor (ICM) procedures have been performed in the cardiac catheterization (CATH) or electrophysiology (EP) laboratory. The introduction of the miniaturized Reveal LINQ ICM has led to simplified and less invasive procedures, affording hospitals flexibility in planning where these procedures occur without compromising patient safety or outcomes. METHODS: The present analysis of the ongoing, prospective, observational, multicenter Reveal LINQ Registry sought to provide real-world feasibility and safety data regarding the ICM procedure performed in the CATH/EP lab or operating room and to compare it with insertions performed outside of these traditional hospital settings. Patients included had at least a 30-day period after the procedure to account for any adverse events. RESULTS: We analyzed 1222 patients (58.1% male, age 61.0 ± 17.1 years) enrolled at 18 centers in the US, 17 centers in Middle East/Asia, and 15 centers in Europe. Patients were categorized into 2 cohorts according to the location of the procedure: in-lab (CATH lab, EP lab, or operating room) (n = 820, 67.1%) and out-of-lab (n = 402, 32.9%). Several differences were observed regarding baseline and procedure characteristics. However, no significant differences in the occurrence of procedure-related adverse events (AEs) were found; of 19 ICM/procedure-related AEs reported in 17 patients (1.4%), 11 occurred in the in-lab group (1.3%) and 6 in the out-of-lab group (1.5%) (P = .80). CONCLUSIONS: This real-world analysis demonstrates the feasibility of performing Reveal LINQ ICM insertion procedures outside of the traditional hospital settings without increasing the risk of infection or other adverse events.

Wireless, battery-free, flexible, miniaturized dosimeters monitor exposure to solar radiation and to light for phototherapy.

Exposure to electromagnetic radiation can have a profound impact on human health. Ultraviolet (UV) radiation from the sun causes skin cancer. Blue light affects the body's circadian melatonin rhythm. At the same time, electromagnetic radiation in controlled quantities has beneficial use. UV light treats various inflammatory skin conditions, and blue light phototherapy is the standard of care for neonatal jaundice. Although quantitative measurements of exposure in these contexts are important, current systems have limited applicability outside of laboratories because of an unfavorable set of factors in bulk, weight, cost, and accuracy. We present optical metrology approaches, optoelectronic designs, and wireless modes of operation that serve as the basis for miniature, low-cost, and battery-free devices for precise dosimetry at multiple wavelengths. These platforms use a system on a chip with near-field communication functionality, a radio frequency antenna, photodiodes, supercapacitors, and a transistor to exploit a continuous accumulation mechanism for measurement. Experimental and computational studies of the individual components, the collective systems, and the performance parameters highlight the operating principles and design considerations. Evaluations on human participants monitored solar UV exposure during outdoor activities, captured instantaneous and cumulative exposure during blue light phototherapy in neonatal intensive care units, and tracked light illumination for seasonal affective disorder phototherapy. Versatile applications of this dosimetry platform provide means for consumers and medical providers to modulate light exposure across the electromagnetic spectrum in a way that can both reduce risks in the context of excessive exposure and optimize benefits in the context of phototherapy.

Low temperature approach for high density electrical feedthroughs for neural implants using maskless fabrication techniques.

Implantable electronic packages for neural implants utilize reliable electrical feedthroughs that connect the inside of a sealed capsule to the components that are exposed to the surrounding body tissue. With the ongoing miniaturization of implants requiring ever higher integration densities of such feedthroughs new technologies have to be investigated. The presented work investigates the sealing of vertical feedthroughs in aluminum-oxide-substrates with gold stud-bumps. The technology enables integration densities of up to 1600/cm 2 while delivering suitable water leak rates for realistic implantation durations of miniaturized packages (feedthrough-count $>50$, package-volume $<2$ cm $^{3})$ of more than 50 years. All manufacturing steps require temperatures below $420 ^{\circ}\mathrm {C}$ and are suitable for maskless rapid prototyping.

Silicon Photonic Biosensors Using Label-Free Detection.

Thanks to advanced semiconductor microfabrication technology, chip-scale integration and miniaturization of lab-on-a-chip components, silicon-based optical biosensors have made significant progress for the purpose of point-of-care diagnosis. In this review, we provide an overview of the state-of-the-art in evanescent field biosensing technologies including interferometer, microcavity, photonic crystal, and Bragg grating waveguide-based sensors. Their sensing mechanisms and sensor performances, as well as real biomarkers for label-free detection, are exhibited and compared. We also review the development of chip-level integration for lab-on-a-chip photonic sensing platforms, which consist of the optical sensing device, flow delivery system, optical input and readout equipment. At last, some advanced system-level complementary metal-oxide semiconductor (CMOS) chip packaging examples are presented, indicating the commercialization potential for the low cost, high yield, portable biosensing platform leveraging CMOS processes.

Is skin microneedling a good alternative method of various skin defects removal.

Skin microneedling accelerates the process of skin regeneration through the creation of numerous microinjuries which emerge when skin is deeply punctured with very thin needles. The whole procedure evokes various reactions which can be divided into three major phases: inflammation, proliferation, and remodeling. It activates platelet growth factors which are responsible for the stimulation of fibroblasts to produce collagen and elastin. Moreover, skin breakdown enhances penetration of active ingredients. Treatment can be performed with the use of different devices, all equipped with needles of various lengths. Due to the fact that skin microneedling stimulates the synthesis of significant rebuilding and structural skin elements (collagen, elastin, proteoglycan), it is used in the treatment of many skin defects of different etiologies (e.g., photoaging, wrinkles, loss of elasticity, hypo- or hypertrophic scars, pigmentation changes, infraorbital dark circles, teleangiectasia, stretch marks, cellulite, alopecia, and vitiligo). In order to accelerate postsurgical regeneration and/or to enhance effects, microneedling is combined with the application of UV light (photodynamic therapy with ALA), LED light, platelet-rich plasma, chemical peels, stem cells, retinoids and other pharmaceuticals, and vitamins. High effectiveness, limited number of side effects, and short recovery time, make skin microneedling a popular cosmetic, and medical treatment.

Supermini nefrolitotomía percutánea para cálculos renales menores de 25 mm en pacientes pediátricos: ¿podría ser una alternativa a la litotricia por ondas de choque? / Super-mini percutaneous nephrolithotomy for renal stone less than 25 mm in pediatric patients: Could it be an alternative to shockwave lithotripsy?

Objetivo: Evaluar la eficacia de 2 técnicas diferentes, la litotricia por ondas de choque (LOC) frente a la supermini nefrolitotomía percutánea (SMP), en términos de éxito y tasas de complicaciones en cálculos renales pediátricos de tamaño < 25 mm. Pacientes y métodos: Se incluyeron un total de 219 niños (edades comprendidas entre uno y 17 años) sometidos a 2 modalidades de tratamiento diferentes (LOC vs. SMP) para cálculos renales < 25 mm. Dependiendo del tipo de procedimiento aplicado, los niños se dividieron en 2 grupos diferentes: grupo 1 (n = 108), formado por niños tratados con LOC, y grupo 2 (n = 111), integrado por niños tratados con SMP. Todos los parámetros relacionados con el tratamiento (tasas libres de cálculos, número de sesiones, duración del tratamiento, hospitalización, presencia de fragmentos residuales, complicaciones así como la necesidad de intervenciones adicionales) se observaron y evaluaron entre 2 grupos de forma comparativa. Resultados: La evaluación de nuestros datos ha demostrado claramente que el porcentaje de fragmentos residuales fue significativamente mayor en los casos sometidos a procedimiento de LOC en comparación con SMP. Aunque LOC requirió varias sesiones bajo anestesia general en un cierto porcentaje de los casos (54,6%), SMP tuvo éxito en una sesión en todos los casos. Por último, pero no por ello menos importante, además de las tasas de complicaciones menores similares observadas en ambos grupos de casos, no se observó ninguna complicación grave y ningún caso requirió transfusión de sangre después de estos 2 procedimientos, sin tasas significativas de descenso en los niveles de hemoglobina. Conclusiones: Aunque la LOC sigue siendo la modalidad de tratamiento preferida para la mayoría de los cálculos renales en niños por su naturaleza segura y no invasiva, la modalidad de SMP puede aplicarse como una alternativa valiosa en esta población específica de pacientes por sus excelentes tasas de ausencia de cálculos obtenidas en una sesión única y tasas de complicaciones aceptables en el manejo invasivo mínimo de cálculos < 25 mm

Aim: To evaluate the efficacy of 2 different techniques: shock wave lithotripsy (SWL) vs. super-mini percutaneous nephrolithotomy (SMP), in terms of success as well as complication rates in pediatric renal stones sizing < 25 mm. Patients and methods: A total of 219 children (aging between 1-17 years) undergoing 2 different treatment modalities (SWL vs. SMP) for kidney stones < 25 mm were included. Depending on the type of the procedure applied, children were divided into 2 different groups: group 1 (n = 108), children treated with SWL, and group 2 (n = 111), children treated with SMP. All treatment related parameters (stone free rates, number of sessions, treatment duration, hospitalization, presence of the residual fragments, complications as well as the need for additional interventions) were noted and evaluated between 2 groups in a comparative manner. Results: Evaluation of our data have clearly demonstrated that the percentage of residual fragments after SWL was significantly higher when compared with SMP. Although SWL required several sessions under general anesthesia in a certain per cent of the cases (54.6%), SMP was successful in one session in all of the cases. Last but not least, in addition to the similar minor complication rates observed in both group of cases, no major complication observed in any case and no case in both groups again required blood transfusion after these 2 procedures with no significant drop rates in hemoglobin levels. Conclusions:Although SWL is still the preferred treatment modality for the majority of kidney stones in children due to its safe and non-invasive nature, SMP modality may be applied as a valuable alternative in this specific patient population for its excellent stone free rates obtained in a single session and acceptable complication rates in the minimal invasive management of stones < 25 mm