Poly(L-lactide)/nano-hydroxyapatite piezoelectric scaffolds for tissue engineering.

The development of bone tissue engineering, a field with significant potential, requires a biomaterial with high bioactivity. The aim of this manuscript was to fabricate a nanofibrous poly(L-lactide) (PLLA) scaffold containing nano-hydroxyapatite (nHA) to investigate PLLA/nHA composites, particularly the effect of fiber arrangement and the addition of nHA on the piezoelectric phases and piezoelectricity of PLLA samples. In this study, we evaluated the effect of nHA particles on a PLLA-based electrospun scaffold with random and aligned fiber orientations.

Development of Poly(methyl methacrylate)/nano-hydroxyapatite (PMMA/nHA) Nanofibers for Tissue Engineering Regeneration Using an Electrospinning Technique.

The study explores the in vitro biocompatibility and osteoconductivity of poly(methyl methacrylate)/nano-hydroxyapatite (PMMA/nHA) composite nanofibrous scaffolds for bone tissue engineering (BTE). Electrospun scaffolds, exhibiting both low and high fiber orientation, were investigated. The inclusion of hydroxyapatite nanoparticles enhances the osteoconductivity of the scaffolds while maintaining the ease of fabrication through electrospinning.

On-Demand Sequential Release of Dual Drug from pH-Responsive Electrospun Janus Nanofiber Membranes toward Wound Healing and Infection Control.

Drugs against bacteria and abnormal cells, such as antibiotics and anticancer drugs, may save human lives. However, drug resistance is becoming more common in the clinical world. Nowadays, a synergistic action of multiple bioactive compounds and their combination with smart nanoplatforms has been considered an alternative therapeutic strategy to fight drug resistance in multidrug-resistant cancers and microorganisms.

A Comprehensive Study of a Novel Explosively Hardened Pure Titanium Alloy for Medical Applications.

Pure titanium is gaining increasing interest due to its potential use in dental and orthopedic applications. Due to its relatively weak mechanical parameters, a limited number of components manufactured from pure titanium are available on the market. In order to improve the mechanical parameters of pure titanium, manufacturers use alloys containing cytotoxic vanadium and aluminum.

Chitosan-Based High-Intensity Modification of the Biodegradable Substitutes for Cancellous Bone.

An innovative approach to treating bone defects is using synthetic bone substitutes made of biomaterials. The proposed method to obtain polylactide scaffolds using the phase inversion technique with a freeze extraction variant enables the production of substitutes with morphology similar to cancellous bone (pore size 100-400 µm, open porosity 94%). The high absorbability of the implants will enable their use as platelet-rich plasma (PRP) carriers in future medical devices.

A facile one-stone-two-birds strategy for fabricating multifunctional 3D nanofibrous scaffolds.

Local bacterial infections lead to delayed wound healing and in extreme cases, such as diabetic foot ulcers, to non-healing due to the impaired cellular function in such wounds. Thus, many scientists have focused on developing advanced therapeutic platforms to treat infections and promote cellular proliferation and angiogenesis. This study presents a facile approach for designing nanofibrous scaffolds in three dimensions (3D) with enhanced antibacterial activity to meet the need of treating chronic diabetic wounds.

Methylcellulose/agarose hydrogel loaded with short electrospun PLLA/laminin fibers as an injectable scaffold for tissue engineering/3D cell culture model for tumour therapies.

This research aimed at designing and fabricating a smart thermosensitive injectable methylcellulose/agarose hydrogel system loaded with short electrospun bioactive PLLA/laminin fibers as a scaffold for tissue engineering applications or 3D cell culture models. Considering ECM-mimicking morphology and chemical composition, such a scaffold is capable of ensuring a hospitable environment for cell adhesion, proliferation, and differentiation. Its viscoelastic properties are beneficial from the practical perspective of minimally invasive materials that are introduced to the body injection.

A Devonian crinoid with a diamond microlattice.

Owing to their remarkable physical properties, cellular structures, such as triply periodic minimal surfaces (TPMS), have multidisciplinary and multifunctional applications. Although these structures are observed in nature, examples of TPMS with large length scales in living organisms are exceedingly rare. Recently, microstructure reminiscent of the diamond-type TPMS was documented in the skeleton of the modern knobby starfish .

Advanced Graft Development Approaches for ACL Reconstruction or Regeneration.

The Anterior Cruciate Ligament (ACL) is one of the major knee ligaments, one which is greatly exposed to injuries. According to the British National Health Society, ACL tears represent around 40% of all knee injuries. The number of ACL injuries has increased rapidly over the past ten years, especially in people from 26-30 years of age.

Multifluid electrospinning for multi-drug delivery systems: pros and cons, challenges, and future directions.

The electrospinning method has been widely used to produce nano/micro fibers for various applications. As a drug delivery system, electrospun fibers display many advantages such as controlled drug delivery kinetics and the ability to deliver drugs locally. A drug delivery system improves delivery efficiency and reduces possible toxic effects.

A methylcellulose/agarose hydrogel as an innovative scaffold for tissue engineering.

crosslinked materials are the main interests of both scientific and industrial research. Methylcellulose (MC) aqueous solution is one of the representatives that belongs to this family of thermosensitive materials. At room temperature, MC is a liquid whereupon during temperature increase up to 37 °C, it crosslinks physically and turns into a hydrogel.

Immobilization of Gelatin on Fibers for Tissue Engineering Applications: A Comparative Study of Three Aliphatic Polyesters.

Immobilization of cell adhesive proteins on the scaffold surface has become a widely reported method that can improve the interaction between scaffold and cells. In this study, three nanofibrous scaffolds obtained by electrospinning of poly(caprolactone) (PCL), poly(L-lactide-co-caprolactone) (PLCL) 70:30, or poly(L-lactide) (PLLA) were subjected to chemical immobilization of gelatin based on aminolysis and glutaraldehyde cross-linking, as well as physisorption of gelatin. Two sets of aminolysis conditions were applied to evaluate the impact of amine group content.

Effect of crystallinity and related surface properties on gene expression of primary fibroblasts.

The biomaterial-cells interface is one of the most fundamental issues in tissue regeneration. Despite many years of scientific work, there is no clear answer to what determines the desired adhesion of cells and the synthesis of ECM proteins. Crystallinity is a characteristic of the structure that influences the surface and bulk properties of semicrystalline polymers used in medicine.

Aminolysis as a surface functionalization method of aliphatic polyester nonwovens: impact on material properties and biological response.

It is reported in the literature that introducing amino groups on the surface improves cellular behaviour due to enhanced wettability and the presence of the positive charge. In this work, electrospun fibers were subjected to aminolysis under various conditions to investigate the impact of reaction parameters on the concentration of free NH groups, change of fiber properties, and the response of L929 cells. Three types of electrospun nonwovens obtained from poly(caprolactone) (PCL), poly(l-lactide--caprolactone) (PLCL) 70 : 30 and poly(l-lactide) (PLLA) were investigated.

Shared patterns in body size declines among crinoids during the Palaeozoic extinction events.

Crinoids were among the most abundant marine benthic animals throughout the Palaeozoic, but their body size evolution has received little attention. Here, we compiled a comprehensive database on crinoid calyx biovolumes throughout the Palaeozoic. A model comparison approach revealed contrasting and complex patterns in body size dynamics between the two major crinoid clades (Camerata and Pentacrinoidea).

Solution-Blown Poly(hydroxybutyrate) and ε-Poly-l-lysine Submicro- and Microfiber-Based Sustainable Nonwovens with Antimicrobial Activity for Single-Use Applications.

Antimicrobial nonwovens for single use applications (e.g., diapers, sanitary napkins, medical gauze, etc.

Shortening of electrospun PLLA fibers by ultrasonication.

This research work is aimed at studying the effect of ultrasounds on the effectiveness of fiber fragmentation by taking into account the type of sonication medium, processing time, and various PLLA molecular weights. Fragmentation was followed by an appropriate filtration in order to decrease fibers length distribution. It was evidenced by fiber length determination using SEM that the fibers are shortened after ultrasonic treatment, and the effectiveness of shortening depends on the two out of three investigated parameters, mostly on the sonication medium, and processing time.

The effect of diameter of fibre on formation of hydrogen bonds and mechanical properties of 3D-printed PCL.

Fused Deposition Modelling (FDM) technique has been widely utilized in fabrication of 3D porous scaffolds for tissue engineering (TE) applications. Surprisingly, although there are many publications devoted to the architectural features of the 3D scaffolds fabricated by the FDM, none of them give us evident information about the impact of the diameter of the fibres on material properties. Therefore, the aim of this study was to investigate, for the first time, the effect of the diameter of 3D-printed PCL fibres on variations in their microstructure and resulting mechanical behaviour.

Experimental neoichnology of post-autotomy arm movements of sea lilies and possible evidence of thrashing behaviour in Triassic holocrinids.

Echinoderms exhibit remarkable powers of autotomy. For instance, crinoids can shed arm and stalk portions when attacked by predators. In some species, it has been reported that the autotomized arms display vigorous movements, which are thought to divert the attention of predators.

Effects of seawater Mg /Ca ratio and diet on the biomineralization and growth of sea urchins and the relevance of fossil echinoderms to paleoenvironmental reconstructions.

It has been argued that skeletal Mg/Ca ratio in echinoderms is mostly governed by Mg and Ca concentrations in the ambient seawater. Accordingly, well-preserved fossil echinoderms were used to reconstruct Phanerozoic seawater Mg /Ca ratio. However, Mg/Ca ratio in echinoderm skeleton can be affected by a number of environmental and physiological factors, the effects of which are still poorly understood.

Poly(Glycerol Succinate) as an Eco-Friendly Component of PLLA and PLCL Fibres towards Medical Applications.

This study was conducted as a first step in obtaining eco-friendly fibres for medical applications using a synthesised oligomer poly(glycerol succinate) (PGSu) as an additive for synthetic poly(L-lactic acid) (PLLA) and poly (L-lactide-co-caprolactone) (PLCL). The effects of the oligomer on the structure formation, morphology, crystallisation behaviour, and mechanical properties of electrospun bicomponent fibres were investigated. Nonwovens were investigated by means of scanning electron microscopy (SEM), wide angle X-ray scattering (WAXS), differential scanning calorimetry (DSC), and mechanical testing.

Poly-L-lactide scaffolds with super pores obtained by freeze-extraction method.

A nonplanar polylactide scaffold to be used in tissue engineering was obtained by freeze-extraction method. Properties of the scaffold were modified by adding Eudragit® E100. The impact of the modification on morphology, porosity and pore size, mass absorbability, mechanical properties was determined.

Novel 3D Hybrid Nanofiber Scaffolds for Bone Regeneration.

Development of hybrid scaffolds and their formation methods occupies an important place in tissue engineering. In this paper, a novel method of 3D hybrid scaffold formation is presented as well as an explanation of the differences in scaffold properties, which were a consequence of different crosslinking mechanisms. Scaffolds were formed from 3D freeze-dried gelatin and electrospun poly(lactide--glicolide) (PLGA) fibers in a ratio of 1:1 w/w.

Crosslinking Kinetics of Methylcellulose Aqueous Solution and Its Potential as a Scaffold for Tissue Engineering.

Thermosensitive, physically crosslinked injectable hydrogels are in the area of interests of various scientific fields. One of the representatives of this materials group is an aqueous solution of methylcellulose. At ambient conditions, methylcellulose (MC) is a sol while on heating up to 37 °C, MC undergoes physical crosslinking and transforms into a gel.

Aminolysis of Various Aliphatic Polyesters in a Form of Nanofibers and Films.

Surface functionalization of polymer scaffolds is a method used to improve interactions of materials with cells. A frequently used method for polyesters is aminolysis reaction, which introduces free amine groups on the surface. In this study, nanofibrous scaffolds and films of three different polyesters-polycaprolactone (PCL), poly(lactide--caprolactone) (PLCL), and poly(l-lactide) (PLLA) were subjected to this type of surface modification under the same conditions.