In Vitro Biocompatibility Assessment of Bioengineered PLA-Hydrogel Core-Shell Scaffolds with Mesenchymal Stromal Cells for Bone Regeneration.

Human mesenchymal stromal cells (hMSCs), whether used alone or together with three-dimensional scaffolds, are the best-studied postnatal stem cells in regenerative medicine. In this study, innovative composite scaffolds consisting of a core-shell architecture were seeded with bone-marrow-derived hMSCs (BM-hMSCs) and tested for their biocompatibility and remarkable capacity to promote and support bone regeneration and mineralization. The scaffolds were prepared by grafting three different amounts of gelatin-chitosan (CH) hydrogel into a 3D-printed polylactic acid (PLA) core (PLA-CH), and the mechanical and degradation properties were analyzed.

Hydrogel-chitosan and polylactic acid-polycaprolactone bioengineered scaffolds for reconstruction of mandibular defects: a preclinical study with assessment of translationally relevant aspects.

Reconstruction of mandibular bone defects is a surgical challenge, and microvascular reconstruction is the current gold standard. The field of tissue bioengineering has been providing an increasing number of alternative strategies for bone reconstruction. In this preclinical study, the performance of two bioengineered scaffolds, a hydrogel made of polyethylene glycol-chitosan (HyCh) and a hybrid core-shell combination of poly (L-lactic acid)/poly ( -caprolactone) and HyCh (PLA-PCL-HyCh), seeded with different concentrations of human mesenchymal stromal cells (hMSCs), has been explored in non-critical size mandibular defects in a rabbit model.

Solvent-triggered shape change in gradient-based 4D printed bilayers: case study on semi-crystalline polymer networks.

We propose an approach to 4D print solvent-triggered, gradient-based bilayers made of semi-crystalline crosslinked polymer networks. Out-of-plane bending is obtained after immersion in the solvent, exploiting the different swelling degrees of the layers resulting from crosslinking gradients. Lastly, a beam model of the shape transformation is applied and experimentally validated.

New Poly(lactic acid)-Hydrogel Core-Shell Scaffolds Highly Support MSCs' Viability, Proliferation and Osteogenic Differentiation.

Scaffolds for tissue engineering are expected to respond to a challenging combination of physical and mechanical requirements, guiding the research towards the development of novel hybrid materials. This study introduces innovative three-dimensional bioresorbable scaffolds, in which a stiff poly(lactic acid) lattice structure is meant to ensure temporary mechanical support, while a bioactive gelatin-chitosan hydrogel is incorporated to provide a better environment for cell adhesion and proliferation. The scaffolds present a core-shell structure, in which the lattice core is realized by additive manufacturing, while the shell is nested throughout the core by grafting and crosslinking a hydrogel forming solution.

Tailoring the properties of composite scaffolds with a 3D-Printed lattice core and a bioactive hydrogel shell for tissue engineering.

The optimal performance of scaffolds for tissue engineering relies on a proper combination of their constituent biomaterials and on the design of their structure. In this work, composite scaffolds with a core-shell architecture are realized by grafting a gelatin-chitosan hydrogel onto a 3D-printed polylactic acid (PLA) core, aiming in particular at bone regeneration. This hydrogel was recently found to sustain osteogenic differentiation of mesenchymal stromal cells, leading to new bone tissue formation.

Expandable Drug Delivery Systems Based on Shape Memory Polymers: Impact of Film Coating on Mechanical Properties and Release and Recovery Performance.

Retentive drug delivery systems (DDSs) are intended for prolonged residence and release inside hollow muscular organs, to achieve either local or systemic therapeutic goals. Recently, formulations based on shape memory polymers (SMPs) have gained attention in view of their special ability to recover a shape with greater spatial encumbrance at the target organ (e.g.

Hybrid Core-Shell Polymer Scaffold for Bone Tissue Regeneration.

A great promise for tissue engineering is represented by scaffolds that host stem cells during proliferation and differentiation and simultaneously replace damaged tissue while maintaining the main vital functions. In this paper, a novel process was adopted to develop composite scaffolds with a core-shell structure for bone tissue regeneration, in which the core has the main function of temporary mechanical support, and the shell enhances biocompatibility and provides bioactive properties. An interconnected porous core was safely obtained, avoiding solvents or other chemical issues, by blending poly(lactic acid), poly(ε-caprolactone) and leachable superabsorbent polymer particles.

Thermoactive Smart Electrospun Nanofibers.

The recent burst of research on smart materials is a clear evidence of the growing interest of the scientific community, industry, and society in the field. The exploitation of the great potential of stimuli-responsive materials for sensing, actuation, logic, and control applications is favored and supported by new manufacturing technologies, such as electrospinning, that allows to endow smart materials with micro- and nanostructuration, thus opening up additional and unprecedented prospects. In this wide and lively scenario, this article systematically reviews the current advances in the development of thermoactive electrospun fibers and textiles, sorting them, according to their response to the thermal stimulus.

Experimental and computational analysis of a pharmaceutical-grade shape memory polymer applied to the development of gastroretentive drug delivery systems.

The present paper aims at developing an integrated experimental/computational approach towards the design of shape memory devices fabricated by hot-processing with potential for use as gastroretentive drug delivery systems (DDSs) and for personalized therapy if 4D printing is involved. The approach was tested on a plasticized poly(vinyl alcohol) (PVA) of pharmaceutical grade, with a glass transition temperature close to that of the human body (i.e.

Expandable drug delivery system for gastric retention based on shape memory polymers: Development via 4D printing and extrusion.

Several diseases would benefit from prolonged drug release provided by systems retained in the stomach for extended time periods. Expandable gastroretentive devices are administered in a collapsed configuration enabling swallowing and regain in situ their native shape having larger spatial encumbrance, thus hindering voidance through the wide open pylorus. An expandable system for gastric retention was here proposed relying on the shape memory behavior of pharmaceutical-grade poly(vinyl alcohol).

Retentive device for intravesical drug delivery based on water-induced shape memory response of poly(vinyl alcohol): design concept and 4D printing feasibility.

The use of shape memory polymers exhibiting water-induced shape recovery at body temperature and water solubility was proposed for the development of indwelling devices for intravesical drug delivery. These could be administered via catheter in a suitable temporary shape, retained in the bladder for a programmed period of time by recovery of the original shape and eliminated with urine following dissolution/erosion. Hot melt extrusion and fused deposition modeling 3D printing were employed as the manufacturing techniques, the latter resulting in 4D printing because of the shape modifications undergone by the printed item over time.

Radiation resistance of elastomeric O-rings in mixed neutron and gamma fields: Testing methodology and experimental results.

Materials and components employed in the presence of intense neutron and gamma fields are expected to absorb high dose levels that may induce deep modifications of their physical and mechanical properties, possibly causing loss of their function. A protocol for irradiating elastomeric materials in reactor mixed neutron and gamma fields and for testing the evolution of their main mechanical and physical properties with absorbed dose has been developed. Four elastomeric compounds used for vacuum O-rings, one fluoroelastomer polymer (FPM) based and three ethylene propylene diene monomer rubber (EPDM) based, presently available on the market have been selected for the test.

Synthesis and Biological Evaluation of New Natural Phenolic (2E,4E,6E)-Octa-2,4,6-trienoic Esters.

In the present study the esterification of the OH groups of resveratrol, caffeic acid, ferulic acid, and β-sitosterol with an antioxidant polyconjugated fatty acid, (2E,4E,6E)-octa-2,4,6-trienoic acid, was achieved. As the selective esterification of OH groups of natural compounds can affect their biological activity, a selective esterification of resveratrol and caffeic acid was performed by an enzymatic approach. The new resulting compounds were characterized spectroscopically (FT-IR, NMR mono, and bidimensional techniques); when necessary the experimental data were integrated by quantum chemical calculations.

Advances in chemoselective intermolecular cross-benzoin-type condensation reactions.

The intermolecular cross-benzoin and acyloin condensation reactions are powerful approaches to α-hydroxy carbonyls in a single step. However, their potentiality suffers from the occurrence of side reactions including self-condensation and the formation of the undesired cross-acyloin. The broad range of azolium salt precatalysts available confers high tunability to NHC mediated benzoin condensation, assuring a good level of selectivity to the direct coupling between two non-equivalent aldehydes.

Whole brain radiotherapy with adjuvant or concomitant boost in brain metastasis: dosimetric comparison between helical and volumetric IMRT technique.

Background: To compare and evaluate the possible advantages related to the use of VMAT and helical IMRT and two different modalities of boost delivering, adjuvant stereotactic boost (SRS) or simultaneous integrated boost (SIB), in the treatment of brain metastasis (BM) in RPA classes I-II patients.

Methods: Ten patients were treated with helical IMRT, 5 of them with SRS after whole brain radiotherapy (WBRT) and 5 with SIB. MRI co-registration with planning CT was mandatory and prescribed doses were 30 Gy in 10 fractions (fr) for WBRT and 15Gy/1fr or 45Gy/10fr in SRS or SIB, respectively.

The treatment of patients with 1-3 brain metastases: is there a place for whole brain radiotherapy alone, yet? A retrospective analysis.

Aim: To evaluate the efficacy of whole brain radiotherapy (WBRT) with or without other treatments in patients (pts) with 1-3 brain metastases (BM).

Materials And Methods: Toxicities and survival of 134 pts treated between 2009 and 2013 with WBRT alone (58 pts), WBRT plus surgery (SUR-WBRT: 42 pts) or WBRT followed by stereotactic or integrated boost radiotherapy (SRT-WBRT: 34 pts) were analyzed. Differences in toxicity (acute and late) incidence and in overall (OS), disease-free (DFS) and disease-specific survival (DSS) were evaluated (χ(2)-test, uni- and multivariate analysis).

Intermediate care as a means of improving mental status in post-acute elderly patients.

Aim Of The Study: To evaluate the impact of residential intermediate care (IC) on the cognitive status of post-acute older patients and its correlation with the improvement in physical independence.

Methods: This prospective observational study involved 299 subjects (116 males and 183 females; mean age 80.1 ± 8.