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Abstract Background The increasing demand for childbirth care based on physiological principles has led official bodies to encourage health centers to provide evidence-based care aimed at promoting women’s participation in informed decision-making and avoiding excessive medical intervention during childbirth. One of the goals is to reduce pain and find alternative measures to epidural anesthesia to enhance women’s autonomy and well-being during childbirth. Currently, water immersion is used as a non-pharmacological method for pain relief. This review aimed to identify and synthesize evidence on women’s and midwives’ experiences, values, and preferences regarding water immersion during childbirth. Methods A systematic review and thematic synthesis of qualitative evidence were conducted. Databases were searched and references were checked according to specific criteria. Studies that used qualitative data collection and analysis methods to examine the opinions of women or midwives in the hospital setting were included. Non-qualitative studies, mixed-methods studies that did not separately report qualitative results, and studies in languages other than English or Spanish were excluded. The Critical Appraisal Skills Program Qualitative Research Checklist was used to assess study quality, and results were synthesized using thematic synthesis. Results Thirteen studies met the inclusion criteria and were included in this review. The qualitative studies yielded three key themes: 1) reasons identified by women and midwives for choosing a water birth, 2) benefits experienced in water births, and 3) barriers and facilitators of water immersion during childbirth. Conclusions The evidence from qualitative studies indicates that women report benefits associated with water birth. From the perspective of midwives, ensuring safe water births requires adequate resources, midwives training, and rigorous standardized protocols to ensure that all pregnant women can safely opt for water immersion during childbirth with satisfactory results.

Abstract Using in vitro, in vivo and patient-based approaches, we investigated the potential of circulating microRNAs (miRNAs) as surrogate biomarkers of myocardial steatosis, a hallmark of diabetic cardiomyopathy. We analysed the cardiomyocyte-enriched miRNA signature in serum from patients with well-controlled type 2 diabetes and with verified absence of structural heart disease or inducible ischemia, and control volunteers of the same age range and BMI (N = 86), in serum from a high-fat diet-fed murine model, and in exosomes from lipid-loaded HL-1 cardiomyocytes. Circulating miR-1 and miR-133a levels were robustly associated with myocardial steatosis in type 2 diabetes patients, independently of confounding factors in both linear and logistic regression analyses (P

Artemisia annua L. is characterized by a strong antimalarial activity due to the presence in its aerial parts of artemisinin and its derivative compounds: dehydroartemisinin and artemisin. These compounds are also antiulcerogenic, antifibroric and antitumoral against P-388 (murine lymphocytic leukemia), A-549 (human lung carcinoma) and HT-29 (human colon adenocarcinoma) cells. annua extract is generally obtained by N-hexane extraction; but, this process is not selective, can induce extract degradation and requires post-processing to eliminate the organic solvent used. In this work, supercritical CO2 (SC-CO2) extraction coupled to fractional separation of a solvent extract is proposed as an eco-friendly alternative to overcome these limitations. In particular, a semi-solid, waxy product (i.e., concrete) from ground A. annua leaves is obtained by hexane extraction; then, it is treated by SC-CO2 selective fractionation and extraction at 90 bar and 50 °C, using a CO2 flow rate of 0.8 kg/h. Operating in this manner, storage and transportation costs can be reduced since the simpler parts of the process (organic solvent extraction and drying) are performed in the area where A. annua is cultivated and the intermediate product (i.e., A. annua concrete) is subsequently delivered to the SC-CO2 plant. Moreover, the volume of the high-pressure extractor is 20 times smaller with respect to the one used to treat the equivalent quantity of vegetable matter by direct SC-CO2 extraction since, in this case, the feed is the organic solvent extract. Therefore, the high-pressure pilot plant will be about 7 times less expensive in terms of equipment involved, if compared with the direct supercritical processing of the ground vegetable material.

The freshness of minimally processed foods is also determined by their appearance; browning due to oxidative phenomena is one of the main reasons of discarded by consumers. To overcame this problem, the development of antioxidant active packaging has gained increasing interest in the food industry. In this work, a supercritical phase inversion process was tested to produce Curcumin (Cu) loaded Cellulose Acetate (CA) membranes, to be inserted in food packaging as antioxidant devices. Active membranes were produced at different process conditions (pressures ranging between 150-250 bar and temperatures ranging between 35-55 °C), polymer amount (12, 18, 24% w/w) and at constant ratio Cu/CA (10% w/w). Cu-loaded membranes showed an homogeneous cellular morphology with a mean pore size lower than 12 µm. Cu release was measured and a maximum release time of about 2 days was obtained; moreover, antioxidant tests were also performed on the loaded membranes, showing an activity up to 90%.

This article focused on the study of the influence of morphological parameters on the mechanical performance (Young’s modulus) of Cellulose Acetate-Graphene Oxide nanocomposites produced by Supercritical CO2 assisted phase inversion, by means of an algorithm managing two parametric variational 3D finite element (FE) models simulating micro- and nano-level of the nanocomposite. Micro-level showed interconnected spherical pores, while nano-level showed a dispersion of not fully exfoliated graphene sheets. 3D FE model exploited the periodic representative volume element (PRVE) concept and accounted for the nanocomposite morphology as determined from Field Emission Scanning Electron Microscopy (FESEM) experiments. Model predictions were compared with experimental results obtained by compression tests at different weight percentages of graphene oxide with respect to the polymer. Once validated, such a FE simulation procedure allows to know in advance which and how to vary the geometrical parameters during the nanocomposite production to improve its final mechanical performance.

In this study, it was evaluated the capability to generate HYAFF membranes by phase inversion assisted by supercritical fluids. HYAFF is a biopolymer, hyaluronic acid ester, much used in the pharmaceutical and biomedical applications. Several techniques have been tested to generate structures (membranes and scaffolds) for biomedical applications; but, all of them present several limitations. For these reasons, supercritical fluids assisted processes have been implemented for biomedical applications. Using SC-CO2 phase inversion process, we obtained HYAFF membranes with different morphological characteristics, depending on the process conditions adopted, such as polymer starting concentrations, pressure (ranging from 90 to 200 bar) and temperature (ranging from 35 to 55°C). The behavior of membranes structure has been studied and has been related to the ternary diagram HYAFF-DMSO-SC-CO2 analyzing the thermodynamic and kinetic aspect of the process.

Cerium acetylacetonate (Ce(acac)3) was precipitated from methanol (MeOH) using supercritical antisolvent process (SAS). The precursor was, then, calcined obtaining the cerium oxide (CeO2). Platinum (Pt) supported on cerium oxide is active for the water gas shift reaction, showing higher activity if compared with platinum supported on other oxides. The catalyst based on platinum supported on cerium oxide obtained using SAS process is more active than the Pt/CeO2 catalyst obtained in a conventional manner. The precursor nanoparticles were precipitated at different pressures and concentrations of the Ce(acac)3/MeOH solution. At the best operating conditions, nanoparticles with a diameter in the range 40-65 nm were obtained. The catalytic activity and the selectivity of two different samples was studied and compared. The catalysts were characterized by X-ray diffraction, field emission scanning electron microscopy, infrared spectroscopy, nitrogen adsorption and desorption at 77 K, and mercury porosimetry.

Liposomes are spherical vesicles formed by a inner aqueous core and a double lipidic layer around it. Conventional techniques for the production of liposomes are characterized by several drawbacks, like the production of micrometric vesicles, a difficult control of the Particle Size Distribution (PSD) and low encapsulation efficiencies (EE) of hydrophilic compounds. Many supercritical semi-continuous techniques were proposed in literature. They are successful in the intent of producing liposomes of smaller diameter, but the EE of hydrophilic compounds and the reproducibility are still a challenge. For this reason, it was recently proposed a new supercritical process whose aim is to invert the steps of production of liposomes, by first creating water droplets and then to fast surround them by phospholipids. We discovered that the high diffusion coefficient of phospholipids in supercritical carbon dioxide allows a fast coverage of water droplets preserving the drug content into the liposome core. In this work, hydrophilic compounds were encapsulated in the vesicles produced using SuperLip, such as Fluorescein, Bovine Serum Albumin (BSA) and Ampicillin, obtaining monodispersed spherical vesicles with a mean size from 100 to 300 nm. Operative parameters like water flow rate and lipid to water mass ratio were optimized. The EEs were evaluated with UV-Vis spectroscopy according to methods reported in literature, and obtaining high values up to 99 % for the three investigated compounds.

Silk fibroin (SF) is a protein that can be used in biomedical field thanks to its biocompatibility, biodegradability and mechanical properties. SF is generally produced in form of aerogel by freeze drying; but, during this process, the delicate nanostructure of the gel can be destroyed, due to the surface tension action on the polymer matrix. The polymer organization at nanoscale (i.e., nanostructure) is preferably required for cells cultivation to ensure their adhesion, differentiation and migration inside the artificial support (i.e., scaffold). In this study, SF aerogels at 10 and 15 % w/w were produced by Supercritical gel drying, potentially useful for nanomedicine applications. SF aerogels were loaded with Ascorbic acid (AA) at 5 % w/w with respect the protein; it was selected since it should favor cell growth and, for example in case of bone tissue engineering applications, for osteoblast differentiation. The obtained aerogels were characterized by scanning electron microscopy and porosity analyses. Moreover, release tests by a spectrophotometer UV/Vis to measure AA release kinetics from SF aerogels and mechanical tests to determine the Young modulus of the produced SF aerogels were also performed. Supercritical assisted process allowed to preserve SF aerogel morphology at nanoscale, thanks to the near zero surface tension of the supercritical mixture (CO2 + organic solvent) at the selected operative conditions (i.e., 200 bar and 35 °C). Moreover, AA release rate can be controlled as well as mechanical properties of the produced aerogels, depending on SF concentration in the starting gel.

In this work an hypothesis of modeling nanofibers network of Poly-L-lactide (PLLA) scaffolds loaded with hydroxyapatite (HA) nanoparticles, suitable for tissue engineering applications, is presented to investigate the mechanical properties by FEM analysis. Scaffolds were produced by Supercritical CO2 drying of polymeric gels. FEM modeling of nanoporous biomaterials involves computational problems such as: the reproduction of the nano-morphology by means of different techniques, such as molecular dynamics simulations that hardly lead to results adherent to the experimental evidence; the reverse engineering to extrapolate geometric information; the identification of a periodic representative volume element (RVE) to reach more coherent results and to reduce the simulation computational effort. Basic modeling assumptions are: a) polymer particles are small enough to exhibit Brownian motion; b) scaffold SEM images show that the porous structure consists of curved fibers that depart from punctiform nuclei realizing a space frame; c) scaffold experimental compressive tests show that the porous material behaves as a soft isotropic material. On the basis of these assumptions, a parametric algorithm that creates a cubic RVE, showing a nanofibers network and having the same porosity of the real material, has been written; RVE size has been optimized on the bases of its material isotropic degree measured by an ad hoc created iterative algorithm for generating a rod spaceframe; RVE mechanical behavior has been optimized by curving appropriately each fiber according to the experimental data and on the basis of SEM imaging diagnostic. Linear FEM simulations on mechanical behavior have given qualitatively and quantitative satisfactory results when compared to the experimental ones.

Los parapléjicos rehabilitados son propensos a sufrir úlceras isquiáticas como complicación más frecuente. Cuando estas úlceras tienen compromiso óseo, su tratamiento solo puede ser quirúrgico. Bajo estas condiciones los colgajos miocutáneos locales son parte de la solución. En el artículo presentamos una serie personal de 10 pacientes parapléjicos rehabilitados con úlceras isquiáticas reconstruidas utilizando un colgajo miocutáneo en isla de la porción inferior del glúteo mayor transferido a través de un túnel subcutáneo. Ninguno de los pacientes de nuestro grupo de estudio sufrió recidiva y todos han tenido una buena evolución a largo plazo. La aportación principal del presente trabajo es hacer hincapié en respetar en estos casos 3 principios utilizados en Cirugía Estética: las incisiones quirúrgicas deben efectuarse en los pliegues naturales para evitar secuelas estético-funcionales; debemos dejar mínimas cicatrices y obtener una restauración volumétrica corporal. En ese sentido pensamos que el diseño de los colgajos debe respetar rigurosamente la orientación del pliegue glúteo y aportar un buen almohadillado para reconstruir el capital volumétrico de la zona glútea; además es primordial dejar pocas cicatrices para no aumentar los riesgos locales debido a la falta de trofismo de la piel. De esta manera, creemos que se evitan las recidivas y las complicaciones.Paraplegic patients, during their rehabilitation period, usually develop ischial ulcers as the most common complication. When there is bone involvement only the surgical approach can be successful. Myocutaneous flaps are part of this approach. We present a sample of 10 paraplegic patients under rehabilitation suffering ischial ulcers that were handled with myocutaneous island flaps obtained from the lower bundles of gluteus maximus and transferred though a subcutaneous tunnel. All these patients have had a long term good evolution with no recurrences. We would like to emphasize that the basic principles of Aesthetic Surgery should be followed: incisions should follow natural creases to avoid aesthetic and functional sequels; leave minimal scar and attain restoration of body volume. We feel that the design of flaps must follow faithfully the gluteal fold orientation and should provide a good mattress to build a good volume on the gluteal area. It is fundamental to leave minimal scarring to avoid the risks of local damages due to the omnipresent degree of atrophy of the skin; thus preventing recurrences and complications.

Las transferencias óseas peroneales en forma libre o ipsilateral han sido propuestas para la reconstrucción de grandes defectos tibiales. Están también descritas varias modificaciones al respecto, siendo una de ellas la constitución de un colgajo compuesto soleo-peroné realizado como transferencia libre. En este estudio presentamos nuestra experiencia con esta variante, pero en forma ipsilateral. logrando la reconstrucción del defecto tibial por medio de la tibialización peroneal. Escogimos realizar un colgajo compuesto soleo-peroné ipsilateral a flujo anterógrado o retrogrado para la reconstrucción de una serie personal de 14 pacientes consecutivos, 13 hombre y 1 mujer, con edad media de 30 años, y con amplios defectos tibiales y de tejidos blandos causados por accidentes de transito en 12 casos, 1 por proyectil balístico y 1 por artefacto explosivo artesanal. El promedio de tamaño del defecto tibial fue de 9.4 cm. Elegimos la forma ipsilateral por no disponer de infraestructura adecuada para realizar una transferencia libre. La serie de estudio se realizó durante el periodo comprendido entre Abril de 1995 y Abril del 2005. Todos los colgajos sobrevivieron. Dos pacientes desarrollaron pseudoartrosis. El apoyo completo y la marcha en 12 pacientes, se logró en un periodo promedio de 9 meses. El seguimiento postoperatorio ha sido de 3 a 6 años. Doce pacientes se han incorporado a la vida activa. Discutimos algunos aspectos prácticos de la técnica como resultado de la experiencia quirúrgica obtenida de esta serie personal. Consideramos que el método es fiable, fácil de realizar y proporciona excelentes resultados.Fibular flaps such as in there free form or as ipsilateral transfers have been proposed for reconstruction of large tibial defects. Several modifications have been described for the use of this flap. In this study we will present our experience using the ipsilateral transfer of an osteomuscular soleous fibular flap for open tibial defect, the bony consolidation was achived with the fibular tibialization. Ipsilateral osteomuscular soleous fibular- flap with an antegrade or retrograde flow was used in the reconstruction of a series of 14 patients with large tibial and soft tissue defects, 13 males and 1 woman. The average age was 30 years. Twelve were injured in motor vehicle accidents one sustained a gun shot wound and the last one sustained injury with home made explosive device. The average tibial defect was 9.5 cm. The decision of doing an ipsilateral transfer flap was due to the inadequate infrastructure of the hospital to perform a free flap. The series was undertaken during the period of april 1995 to april of 2005. All the flaps survived but 2 patients developed a pseudoarthrosis. Bony consolidation was achived in a average time of 9 months. Follow-up time was of 3 to 6 years. Twelve patients kept there limbs intact and were reincorporated to there routine lifes. In this paper we discussed some practical aspects of the surginal techniques. We think that this method of reconstruction of large tibial defects is reliable and easy to perform with exellent results.

The supercritical antisolvent process (SAS) has been frequently used to obtain microparticles and nanoparticles. The fluid dynamics of the process related to the study of the liquid jet in contact with supercritical carbon dioxide (scCO2) is characterized by a one-phase mixing at supercritical conditions and a two-phase mixing at subcritical conditions. The transition between the two kinds of mixing can be measured in terms of amplitude of the corresponding pressure range; some organic solvents, like dimethylsulfoxide (DMSO) are characterized by a wide pressure range, other solvents, like acetone (AC), by a narrow pressure range. Generally, microparticles are precipitated by atomization, droplets formation and drying in the transition range, whereas nanoparticles are precipitated in correspondence of completely developed supercritical conditions. Mixing a wide-transition solvent, like DMSO, to a narrow-transition solvent, like acetone, the pressure range of the transition from one-phase mixing to two-phase mixing and, accordingly, the morphology of the precipitates will change. In this work, two model compounds were SAS processed from DMSO/AC mixtures: cellulose acetate, which is slightly soluble in DMSO and freely soluble in acetone with the aim of obtaining microparticles and polyvinylpyrrolidone (PVP) that is slightly soluble in acetone and freely soluble in DMSO in order to obtain nanoparticles. In the case of cellulose acetate, well-defined microparticles with a mean diameter of 0.42 µm were obtained, whereas, for PVP, nanoparticles with a mean diameter of 114 nm were precipitated, demonstrating that this SAS strategy is successful.

Aerogel-based scaffolds are frequently used for tissue engineering applications, since their nanofibrous structure is suitable for cells adhesion, proliferation and migration. Nevertheless, to achieve proper physico- chemical characteristics and desired mechanical properties, can be necessary to use more polymers together; among them, natural polymers are preferable because they are biocompatible, non-toxic, biodegradable and mucoahesive. In this study, bi-component natural aerogels Alginate-Gelatin (A/G) and Chitosan-Gelatin (CS/G) have been produced by Supercritical gel drying. The results indicate that both A/G and CS/G mixtures formed uniform gels during the preparation step and Supercritical gel drying preserved their delicate nanostructured morphology, thanks to the near zero surface tension of supercritical mixture (CO2 + organic solvent) formed during the drying process, as observed from FESEM pictures. All the aerogels were characterized by porosity values higher than 80%. Moreover, CS/G aerogels crosslinked with Glutaraldehyde (GTA) showed improved thermal behavior increasing gelatin content inside the starting hydrogel.

Supercritical fluids based processes were frequently proposed to realize new kind of supports to deliver poor water-soluble drugs. In some cases, nanostructured aerogels were used as substrates. The matrices constituting the aerogel have to present a high porosity and a high surface area. Different natural and synthetic polymers were used in form of aerogels. Natural polymer-based materials are preferable for their renewability and for environmental reasons; among them, starch is the second most abundant after cellulose and it is attractive for its low cost. In this work, different sources starches (maize, potato and wheat) aerogels were produced using a supercritical carbon dioxide based process. First, a gel is formed by an aqueous solution (hydrogel), then water is replaced by ethanol to form an alcogel; finally, a supercritical gel-drying step is proposed to form the aerogel. The different sources starches were processed and characterized from a macroscopic and a microscopic point of view. The analyses confirmed that the supercritical gel drying process is suitable to form polymeric nanostructured matrices that can be used for delivery systems.

In this study, antimicrobial membranes of cellulose acetate (CA) loaded with potassium sorbate (Psb) were generated by supercritical assisted phase inversion for active packaging applications. To achieve appropriate membranes morphology, the starting solutions were prepared by dissolving Psb in water, and then, adding it to CA-Acetone solution and were processed at different pressures and temperatures. The loaded membranes were analyzed by FESEM, EDX and UV/VIS spectrophotometer, to determine: membrane morphology, distribution of the active compound inside the polymeric matrix and Psb release rate, respectively. The results indicate that, by changing the operative conditions (ranging from 150 to 250 bar, and 35 to 55 °C), cellular structures characterized by different pore size were obtained. EDX analyses showed as the active compound was uniformly distributed in the polymeric matrix at all process conditions tested. Moreover, Psb release time was influenced by membranes morphology, since the active compound diffusion was slowered when the polymer matrix was denser. These results suggest that the antimicrobial membranes, prepared in this study, could be used as food packaging material achieving a controlled release of the active compound, improving the food quality and safety.

En este artículo se presenta la descripción clínica y los hallazgos radiológicos de un caso de pulgar flotante parcialmente tratado en su infancia. Además se plantean las líneas generales a seguir de forma previa al tratamiento ante una malformación congénita del miembro superior y específicamente a nivel de la mano y del pulgar, destacando la clasificación y valoración de los aspectos estético-funcionales. Posteriormente se plantean las conductas quirúrgicas que pueden seguirse y los resultados obtenidos en el caso tratado.This paper deals with the clinical and radiological findings in a case of floating thumb, whose treatment began in the childhood. The general approach to the upper limb and particularly hand and thumb congenital malformations is outlined, as well as their classification and assessment of the cosmetic and functional aspects. Finally the different surgical approaches to this pathology are mentioned and the results obtained in the present case are shown.

Ethyl Cellulose scaffolds were prepared using a supercritical fluid phase inversion process in which carbon dioxide acts as the non-solvent. Ethyl Cellulose is a derivative of cellulose in which some of the hydroxyl groups on the repeating glucose units are converted into ethyl ether groups; it is a biocompatible but non-biodegradable polymer. It is an extensively studied encapsulating material for the controlled release of pharmaceuticals in tissue engineering applications. Series of experiments were performed at various polymer concentrations, temperatures, pressures, and kind of organic solvent. The structures of the resulting scaffolds were analysed using scanning electron microscopy. We operated with polymer concentrations ranging between 5 and 20 % w/w, using N-methyl pyrrolidone and chloroform as organic solvents and we obtained scaffolds characterized by homogeneous cellular structures with different pore mean size. The mean diameter of the pores ranged from 3 µm to 15 µm, decreasing the polymer concentration from 20 to 5 % w/w. Additional experiments were performed varying the operating pressure from 100 and 200 bar, and varying the operating temperature from 35 to 55 °C. Increasing pressure and/or decreasing temperature, the scaffolds pore size largely decreases; both the effects can be related to carbon dioxide density modification. Ethyl Cellulose scaffolds formation mechanisms were also discussed.

Poly (methyl methacrylate) (PMMA) is a polymer largely used in tissue engineering applications. It has a good degree of compatibility with human tissues. A relevant biomedical application of PMMA is represented by the production of scaffolds to be used as controlled release devices for pharmaceutical products. Loaded PMMA scaffolds were prepared using a supercritical fluid-phase separation process, in which CO2 acts as the non-solvent. Supercritical carbon dioxide (SC-CO2) phase separation process has several advantages with respect to traditional scaffold formation processes (foaming, electrospinning, phase separation, etc); for this reason, in this work we tested this method to produce PMMA scaffolds loaded with two different pharmaceutical compounds: Cefuroxime and Diclofenac sodium, respectively, an antibiotic and an anti-inflammatory drug. We prepared PMMA scaffolds using two different procedures: dissolving PMMA and Diclofenac sodium in acetone or suspending Cefuroxime in the organic solution formed by PMMA and acetone. The effect of the drug concentration on scaffold morphology and pore size was analyzed. The obtained scaffolds, produced in correspondence of various drug loadings, were characterized by SEM, to study the morphology and pore size, and by EDX to analyze the drug distribution in the scaffolds. Some drug release rate analyses were also performed, observing very different release behaviors, depending of the solution/suspension process adopted. The results obtained confirmed the feasibility of the loading process and the advantages with respect to traditional methods: efficient encapsulation of the drug and absence of burst effects.

In this paper, different polymers were processed using a Batch Supercritical AntiSolvent precipitation (BSAS) to evaluate the possibility of producing nanoparticles and microparticles of controlled size and distribution. Liquid solutions of a polymer in dimethylsulfoxide (DMSO) or acetone were charged in a vessel; then, supercritical CO2 with the role of antisolvent was pumped up to the desired pressure. The process was performed in two steps: in batch mode for a time t1 and in continuous mode for a time t2, with a constant CO2 flow rate. All the experiments were carried out at a final pressure of 100 bar and a final temperature of 40 °C, whereas the concentration of the liquid solution was varied from 0.1 to 5 mg/mL. SEM images of the processed material were used to study morphology, mean particle size and particle size distribution. Amorphous particles were obtained at all successful BSAS conditions, whereas crystals were sometimes observed when the micronization process failed. Polymers solubilized in acetone, such as cellulose acetate, ethyl cellulose, polymethyl methacrylate (PMMA) and Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) prevalently precipitated in form of nanoparticles in the range 50-200 nanometers, whereas polymers solubilized in DMSO, such as Poly-vinyl-alcohol (PVA), dextran and inulin precipitated in form of nanoparticles at lower concentrations (in the range 100-200 nanometers) and in form of microparticles at higher concentrations (in the range 0.7-2 µm).

Tissue engineering (TE) is an emerging field aimed at repairing defective tissues and organ, instead of relying on conventional organ transplantation. Among the polymeric materials proposed for TE applications, the water-soluble polymers have been frequently used in form of hydrogels, that are a class of highly hydrated polymer materials. Nevertheless, hydrogel materials have poor mechanical properties; as a result, this scaffolding approach is seldom used for hard tissues applications. With the aim of overcoming this limitation, drying processes have been often applied to eliminate the water from hydrogels and amply the range of applications of the water-soluble polymeric scaffolds, but these techniques present several limitations. For this reason, in this work we proposed a supercritical gel drying method coupled with a water/solvent substitution step. PVA, Alginate and Chitosan hydrogels were processed and opportunely characterized from a macroscopic and microscopic point of view. Supercritical gel drying process confirmed to be effectiveness for the formation of polymeric scaffolds; in particular, we obtained stable 3-D structures with nanometric porous morphologies suitable for TE applications.