Development of Bioactive Hybrid Poly(lactic acid)/Poly(methyl methacrylate) (PLA/PMMA) Electrospun Fibers Functionalized with Bioglass Nanoparticles for Bone Tissue Engineering Applications.

Hybrid scaffolds that are based on PLA and PLA/PMMA with 75/25, 50/50, and 25/75 weight ratios and functionalized with 10 wt.% of bioglass nanoparticles (n-BG) were developed using an electrospinning technique with a chloroform/dimethylformamide mixture in a 9:1 ratio for bone tissue engineering applications. Neat PLA and PLA/PMMA hybrid scaffolds were developed successfully through a (CF/DMF) solvent system, obtaining a random fiber deposition that generated a porous structure with pore interconnectivity.

Development of Biocompatible Digital Light Processing Resins for Additive Manufacturing Using Visible Light-Induced RAFT Polymerization.

Patients with bone diseases often experience increased bone fragility. When bone injuries exceed the body's natural healing capacity, they become significant obstacles. The global rise in the aging population and the escalating obesity pandemic are anticipated to lead to a notable increase in acute bone injuries in the coming years.

Fabrication and Testing of Multi-Hierarchical Porous Scaffolds Designed for Bone Regeneration via Additive Manufacturing Processes.

Bone implants or replacements are very scarce due to the low donor availability and the high rate of body rejection. For this reason, tissue engineering strategies have been developed as alternative solutions to this problem. This research sought to create a cellular scaffold with an intricate and complex network of interconnected pores and microchannels using salt leaching and additive manufacturing (3D printing) methods that mimic the hierarchical internal structure of the bone.

Innovation in Additive Manufacturing Using Polymers: A Survey on the Technological and Material Developments.

This review summarizes the most recent advances from technological and physico-chemical perspectives to improve several remaining issues in polymeric materials' additive manufacturing (AM). Without a doubt, AM is experimenting with significant progress due to technological innovations that are currently advancing. In this context, the state-of-the-art considers both research areas as working separately and contributing to developing the different AM technologies.

Three-Dimensional Whole-Organ Characterization of the Regional Alveolar Morphology in Normal Murine Lungs.

Alveolar architecture plays a fundamental role in the processes of ventilation and perfusion in the lung. Alterations in the alveolar surface area and alveolar cavity volume constitute the pathophysiological basis of chronic respiratory diseases such as pulmonary emphysema. Previous studies based on micro-computed tomography (micro-CT) of lung samples have allowed the geometrical study of acinar units.

Wrinkling on Stimuli-Responsive Functional Polymer Surfaces as a Promising Strategy for the Preparation of Effective Antibacterial/Antibiofouling Surfaces.

Biocompatible smart interfaces play a crucial role in biomedical or tissue engineering applications, where their ability to actively change their conformation or physico-chemical properties permits finely tuning their surface attributes. Polyelectrolytes, such as acrylic acid, are a particular type of smart polymers that present pH responsiveness. This work aims to fabricate stable hydrogel films with reversible pH responsiveness that could spontaneously form wrinkled surface patterns.

Biocompatible fluorinated wrinkled hydrogel films with antimicrobial activity.

Surface-modified hydrogel films were designed to control the bacterial colonization on their surface and to promote cell proliferation through the gradual insertion of highly hydrophobic functional monomers. These hydrogel films were deposited via spin-coating technique, using muscovite mica as a substrate. These samples were then exposed to different external stimuli to produce wrinkled patterns.

Progression of regional lung strain and heterogeneity in lung injury: assessing the evolution under spontaneous breathing and mechanical ventilation.

Background: Protective mechanical ventilation (MV) aims at limiting global lung deformation and has been associated with better clinical outcomes in acute respiratory distress syndrome (ARDS) patients. In ARDS lungs without MV support, the mechanisms and evolution of lung tissue deformation remain understudied. In this work, we quantify the progression and heterogeneity of regional strain in injured lungs under spontaneous breathing and under MV.

Mapping regional strain in anesthetised healthy subjects during spontaneous ventilation.

Introduction: Breathing produces a phenomenon of cyclic deformation throughout life. Biomechanically, deformation of the lung is measured as strain. Regional strain recently started to be recognised as a tool in the study of lung pathophysiology, but regional lung strain has not been studied in healthy subjects breathing spontaneously without voluntary or pharmacological control of ventilation.

Microwrinkled pH-sensitive hydrogel films and their role on the cell adhesion/proliferation.

In this work, hydrogels based on HEMA and DMAEMA (pH-sensitive monomer) were used to form biocompatible films which present microwrinkled patterns in their surface, with the focus of exploring the role of chemical composition on cell adhesion and proliferation. Three different pH (5.4, 7.

The role of three-dimensionality and alveolar pressure in the distribution and amplification of alveolar stresses.

Alveolar stresses are fundamental to enable the respiration process in mammalians and have recently gained increasing attention due to their mechanobiological role in the pathogenesis and development of respiratory diseases. Despite the fundamental physiological role of stresses in the alveolar wall, the determination of alveolar stresses remains challenging, and our current knowledge is largely drawn from 2D studies that idealize the alveolar septal wall as a spring or a planar continuum. Here we study the 3D stress distribution in alveolar walls of normal lungs by combining ex-vivo micro-computed tomography and 3D finite-element analysis.

Antimicrobial Polymers for Additive Manufacturing.

Three-dimensional (3D) printing technologies can be widely used for producing detailed geometries based on individual and particular demands. Some applications are related to the production of personalized devices, implants (orthopedic and dental), drug dosage forms (antibacterial, immunosuppressive, anti-inflammatory, etc.), or 3D implants that contain active pharmaceutical treatments, which favor cellular proliferation and tissue regeneration.

Micrometric Wrinkled Patterns Spontaneously Formed on Hydrogel Thin Films via Argon Plasma Exposure.

The generation of microstructured patterns on the surface of a specific polymeric material could radically improve their performance in a particular application. Most of the interactions with the environment occur at the material interface; therefore, increasing the exposed active surface considerably improves their range of application. In this article, a simple and reliable protocol to form spontaneous wrinkled patterns using a hydrogel layer is reported.

Design and fabrication of biocompatible wrinkled hydrogel films with selective antibiofouling properties.

In this article, we explored the selective antibiofouling capacity acquired by functional wrinkled hydrogel films via a fine tuning of their chemical structure through the gradual insertion of hydrophobic radical groups in their network. The hydrogel consists of three main components: hydroxyethyl methacrylate (HEMA, amphiphilic monomer), trifluoroethyl methacrylate (TFMA, hydrophobic monomer), and poly(ethylene glycol) diacrylate (PEGDA, hydrophilic crosslinking agent). Interestingly, the manipulation of the chemical composition affects both, surface morphology and physicochemical characteristics of the patterns, inducing transitions between different surface microstructures, i.

Smart pH-Responsive Antimicrobial Hydrogel Scaffolds Prepared by Additive Manufacturing.

We report on the fabrication of 3D printed pH-responsive and antimicrobial hydrogels with a micrometer-scale resolution achieved by stereolithography (SLA) 3D printing. The preparation of the hydrogels was optimized by selecting the most appropriate difunctional polyethylene glycol dimethacrylates (testing cross-linking agents with chain lengths ranging from 2 up to 14 units ethylene glycol) and introducing acrylic acid (AA) as a monofunctional monomer. As a result of the incorporation of AA, the hydrogels described are able to reversibly swell and shrink upon environmental changes on the pH, and the swelling extent is directly related to the amount of AA and can be thus finely tuned.

Silylated oligomeric poly(ether-azomethine)s from monomers containing biphenyl moieties: synthesis and characterization.

In this study, four new silicon-containing poly(ether-azomethine)s with linear structures were prepared using original silicon and biphenyl moiety-containing monomers: two diamines and two dialdehydes. The oligomeric natures of the samples were established by GPC analysis, which showed chains containing 3 to 5 repetitive units. The monomers and the oligomeric samples were structurally characterized by NMR and FT-IR spectroscopy.

Strategies to Fabricate Polypeptide-Based Structures via Ring-Opening Polymerization of N-Carboxyanhydrides.

In this review, we provide a general and clear overview about the different alternatives reported to fabricate a myriad of polypeptide architectures based on the ring-opening polymerization of -carbonyanhydrides (ROP NCAs). First of all, the strategies for the preparation of NCA monomers directly from natural occurring or from modified amino acids are analyzed. The synthetic alternatives to prepare non-functionalized and functionalized NCAs are presented.

Thermal Response Analysis of Phospholipid Bilayers Using Ellipsometric Techniques.

Biomimetic planar artificial membranes have been widely studied due to their multiple applications in several research fields. Their humectation and thermal response are crucial for reaching stability; these characteristics are related to the molecular organization inside the bilayer, which is affected by the aliphatic chain length, saturations, and molecule polarity, among others. Bilayer stability becomes a fundamental factor when technological devices are developed-like biosensors-based on those systems.

Advances in the Fabrication of Antimicrobial Hydrogels for Biomedical Applications.

This review describes, in an organized manner, the recent developments in the elaboration of hydrogels that possess antimicrobial activity. The fabrication of antibacterial hydrogels for biomedical applications that permits cell adhesion and proliferation still remains as an interesting challenge, in particular for tissue engineering applications. In this context, a large number of studies has been carried out in the design of hydrogels that serve as support for antimicrobial agents (nanoparticles, antibiotics, etc.

Thin and ordered hydrogel films deposited through electrospinning technique; a simple and efficient support for organic bilayers.

Thermal behavior of Dipalmitoylphosphatidylcholine (DPPC) bilayers deposited over hydrogel fibers was examined. Thus, membrane stability, water absorption-release, phase transitions and phase transition temperatures were studied through different methods during heating cycles. Hydrogel films were realized using an oligomer mixture (HEMA-PEGDA575/photo-initiator) with adequate viscosity.