Multiphysics simulation of liposome release from hydrogels for cavity filling following patient-specific breast tumor surgery.

Several studies have recommended the use of hydrogels for localized targeted delivery of chemotherapeutic drugs following tumor removal surgery. This approach aims to both fill the cavity and prevent cancer recurrence. The use of Multiphysics-based simulation emerges as a valuable strategy for minimizing experimental work, providing detailed insights into how drug release occurs in the tissue, and enabling the optimization of the design.

Multi-physics numerical simulation study on thermo-sensitive gel delivery for a local post-tumor surgery treatment.

Numerous studies in the literature have proposed the use of thermo-responsive hydrogels for filling cavities after tumor resection. However, optimizing the injection process is challenging due to the complex interplay of various multi-physics phenomena, such as the coupling of flow and heat transfer, multi-phase interactions, and phase-change dynamics. Therefore, gaining a fundamental understanding of these processes is crucial.

Controlling particle size of levan in powder form with different technologies.

Levan is a fructose polysaccharide with multiple applications in different fields, but its obtaining in powdered form with a narrow particle size distribution is a complicated task. Two techniques, electrospraying and supercritical antisolvent (SAS) precipitation, were used to process levan that was first obtained enzymatically. The SAS process was able to micronize the polymer (at experimental conditions far above the mixture critical point of the solvent-antisolvent system) to obtain spherical particles between 0.

Development of a thermosensitive hydrogel based on Polaxamer 407 and gellan gum with inclusion complexes (Sulfobutylated-β-cyclodextrin-Farnesol) as a local drug delivery system.

This work proposes the development of a thermosensitive local drug release system based on Polaxamer 407, also known as Pluronic® F-127 (PF-127), Gellan Gum (GG) and the inclusion complex Sulfobutylated-β-cyclodextrin (CD) with Farnesol (FOH). Rheological properties of the hydrogels and their degradation were studied. According to the rheological results, a solution of 20% w/v of PF-127 forms a strong gel with a gelling temperature of about 25 °C (storage modulus of 15,000 Pa).

Supercritical impregnation of starch aerogels with quercetin: Fungistatic effect and release modelling with a compartmental model.

This work proposes the use of supercritical CO to impregnate starch (potato and corn) aerogels with quercetin for a potential fungistatic application. Starch aerogels were successfully produced with supercritical drying, but different results were found depending on the amylose/amylopectin ratio. A higher amount of amylose increases aerogels' specific surface area (with a structure with nanofibrils and nodes) due to the linear and amorphous character of this polymer, whereas a higher amount of amylopectin decreases this property until values of only 25 m·g, obtaining an aerogel with a rough surface.

Engineering Alginate-Based Dry Powder Microparticles to a Size Suitable for the Direct Pulmonary Delivery of Antibiotics.

The inhaled route is regarded as one of the most promising strategies as a treatment against pulmonary infections. However, the delivery of drugs in a dry powder form remains challenging. In this work, we have used alginate to form microparticles containing an antibiotic model (colistin sulfate).

Validation of a compartmental model to predict drug release from porous structures produced by ScCO techniques.

A global release model is proposed to study the drug release from porous materials for pharmaceutical applications. This model is defined by implementing a compartmental model where the release profile could be explained as the combination of mass transfer phenomena through three compartments as well as a desorption process or dissolution process from the support. This model was validated with five different systems produced with supercritical CO (aerogels, membranes, and fibers), showing different release processes.

Tuning Alginate Microparticle Size via Atomization of Non-Newtonian Fluids.

A new approach based on the atomization of non-Newtonian fluids has been proposed to produce microparticles for a potential inhalation route. In particular, different solutions of alginate were atomized on baths of different crosslinkers, piperazine and barium chloride, obtaining microparticles around 5 and 40 microns, respectively. These results were explained as a consequence of the different viscoelastic properties, since oscillatory analysis indicated that the formed hydrogel beads with barium chloride had a higher storage modulus (1000 Pa) than the piperazine ones (20 Pa).

Biopesticide Encapsulation Using Supercritical CO: A Comprehensive Review and Potential Applications.

As an alternative to synthetic pesticides, natural chemistries from living organisms, are not harmful to nontarget organisms and the environment, can be used as biopesticides, nontarget. However, to reduce the reactivity of active ingredients, avoid undesired reactions, protect from physical stress, and control or lower the release rate, encapsulation processes can be applied to biopesticides. In this review, the advantages and disadvantages of the most common encapsulation processes for biopesticides are discussed.

Steady and Oscillatory Shear Flow Behavior of Different Polysaccharides with Laponite.

The rheological behavior, in terms of steady and oscillatory shear flow, of Laponite with different polysaccharides (alginate, chitosan, xanthan gum and levan) in salt-free solutions was studied. Results showed that a higher polymer concentration increased the zero-rate viscosity and decreased the critical strain rate (Cross model fit) as well as increasing the elastic and viscous moduli. Those properties (zero-rate viscosity and critical strain rate) can be a suitable indicator of the effect of the Laponite on the shear flow behavior for the different solutions.

Microbial Exopolysaccharides as Drug Carriers.

Microbial exopolysaccharides are peculiar polymers that are produced by living organisms and protect them against environmental factors. These polymers are industrially recovered from the medium culture after performing a fermentative process. These materials are biocompatible and biodegradable, possessing specific and beneficial properties for biomedical drug delivery systems.

Supercritical carbon dioxide techniques for processing microbial exopolysaccharides used in biomedical applications.

Microbial exopolysaccharides are polymers that show a great potential for biomedical applications, such as tissue engineering applications and drug delivery, due to their biocompatibility, biodegradability and their gelling properties. These polysaccharides are obtained from a microorganism culture with a relatively straightforward downstream process thanks to their extracellular character, and can be processed to obtain aerogels, fibers and micro- or nano-particles with conventional techniques. However, these techniques present several disadvantages in that they involve time-consuming processes and the use of toxic solvents.

Role of rheological properties on physical chitosan aerogels obtained by supercritical drying.

Chitosan aerogels were obtained after using supercritical carbon dioxide to dry physical hydrogels, studying the effect of the rheological behavior of hydrogels and solutions on the final aerogels properties. An increase on the solutions pseudoplasticity increased the subsequent hydrogels physical entanglement, without showing a significant effect on aerogels morphology (nanoporous) and textural properties (pores of about 10 nm). However, an increase of hydrogel physical entanglement promoted the formation of aerogels with a higher compressive strength (from 0.

A comprehensive study on levan nanoparticles formation: Kinetics and self-assembly modeling.

Levan nanoparticles formation is a complicated phenomenon involving simultaneously polymeric reaction kinetics and nanoparticles self-assembly theory. These phenomena are studied in this work with experimental and computational methodologies. Specifically, the effect of different parameters on levan kinetics and nanoparticles production in a cell-free system environment have been studied.

Differences in levan nanoparticles depending on their synthesis route: Microbial vs cell-free systems.

Differences between the levan obtained from bacteria and from cell-free systems were studied in this work. Results showed that both polymers are non-porous solids (type II isotherm with 20 m/g) with a main thermal decomposition at 200 °C and a negligible value of protein adsorption. Microbial levan produced nanoparticles of 90 nm in diameter whereas nanoparticles of 110 nm were obtained with the polymer obtained from a cell-free system.

A Phenomenological Approach to Study Mechanical Properties of Polymeric Porous Structures Processed Using Supercritical CO₂.

This work proposes a modeling of the mechanical properties of porous polymers processed by scCO₂, using a phenomenological approach. Tensile and compression tests of alginate/gelatin and cellulose acetate/graphene oxide were modeled using three hyperelastic equations, derived from strain energy functions. The proposed hyperelastic equations provide a fair good fit for mechanical behavior of the nanofibrous system alginate/gelatin (deviations lower than 10%); whereas, due to the presence of the solid in the polymer network, a four-parameter model must be used to fit the composite cellulose acetate/graphene oxide behavior.

Levan-Capped Silver Nanoparticles for Bactericidal Formulations: Release and Activity Modelling.

An environmentally friendly technique was used to produce levan-capped silver nanoparticles of about 30 nm (with a loading of 30%) that showed bactericide effect, for and . That effect was mathematically studied with a dose-response model (lethal dose of 12.4 ppm and 6.

Effect of bacteria type and sucrose concentration on levan yield and its molecular weight.

Background: Levan has been traditionally produced from microorganism. However, there is a continuous effort in looking for new strains that improve levan production yield and uses alternative sugar sources for growth. Despite having a wide range of data about levan yield, there are not papers which allow controlling molecular weight, and that plays an essential role for further applications.

Development of a nanoparticle system based on a fructose polymer: Stability and drug release studies.

New drug delivery systems (DDSs) with levan or its carboxymethylated form, as carriers, and 5-fluorouracil as a drug, are produced in this work. Levan is obtained after cultivating A. nectaris and polymer nanoparticles are created in water by a self-assembled process.

Effect of nitrogen source on growth and lipid accumulation in Scenedesmus abundans and Chlorella ellipsoidea.

Discovering microalgae strains containing a high lipid yield and adequate fatty acid composition is becoming a crucial fact in algae-oil factories. In this study, two unknown strains, named Scenedesmus abundans and Chlorella ellipsoidea, have been tested for their response to different nitrogen sources, in order to determine its influence in the production of lipids. For S.

Comparative morphology and morphometric assessment of the Neandertal occipital remains from the El Sidrón site (Asturias, Spain: years 2000-2008).

This paper analyses the occipital remains recovered from the El Sidrón (Asturias, Spain) Neandertal site between the years of 2000-2008. The sample is represented by three specimens, SD-1219, SD-1149, and SD-370a. Descriptive morphology, linear measurements, 3D geometric morphometrics, and virtual anthropological methods were employed to address the morphological, morphometric, and phylogenetic affinities of these fossils.