Laponite as a rheology modifier of alginate solutions : physical gelation and aging evolution

The rheological behavior of alginate and Laponite/alginate solutions was studied. It was observed that the Cross viscosity model successfully describes the steady-state shear behavior of this polysaccharide. The scaling behavior analyzed for the entangled regime is in good agreement with polyelectrolyte solutions , with interactions generated between the alginate and the charged surfaces of the Laponite platelets. Therefore, the effect of Laponite as a rheology modifier is influenced by the alginate concentration. Higher alginate concentrations hindered the formation of the house of cards microstructure. Frequency sweep tests were performed to analyze the transition from solid-like to liquid-like behavior in a solid-like dominated domain. Soft physical gels were obtained at low alginate concentrations. The gel point was determined (1.65 wt.% of alginate and 2 wt.% of Laponite) through the Kramers–Krönig damping factor, and time sweep tests revealed the evolution of the storage (G′) and loss modulus (G″) as functions of the waiting time . The growing elasticity revealed that Laponite/alginate solutions undergo aging15718CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ401297/2014-4; 308660/2015-

Can porous polymeric scaffolds be functionalized by stem cells leading to osteogenic differentiation? a systematic review of in vitro studies

The aim of this study was to analyze the influence of nanoporous structure of polymeric biomaterials on the in vitro osteogenic induction of human stem cells. An electronic search in three databases (MEDLINE, SCOPUS, and Web of Science) was performed for articles that were published before May 2018. In vitro studies were included if they met the following criteria: (1) the use of polymeric scaffolds (natural or synthetic); (2) the co-culture of human stem cells with the scaffold; and (3) cell viability, proliferation, and osteogenic differentiation assays. The main characteristics of the published studies were summarized, and a quality assessment tool was used to analyze methodological features. Eighty-eight potential articles were firstly retrieved. Thirteen were eligible for qualitative analysis. Only three studies characterized cell stemness. Nanostructure of the scaffolds showed a significant influence on viability, proliferation, and osteogenic differentiation of human stem cells. Combination of porosity between 72 and 93% and a large range diameter between 50 and 224 μm resulted in more remarkable cellular proliferation and differentiation. Porous polymeric scaffolds can be functionalized by stem cells leading to osteogenic induction. High standards of laboratory practice and accurate methodological reporting are essential for the credibility of the results157571576

Polymeric Biomaterials for Topical Drug Delivery in the Oral Cavity: Advances on Devices and Manufacturing Technologies

There are several routes of drug administration, and each one has advantages and limitations. In the case of the topical application in the oral cavity, comprising the buccal, sublingual, palatal, and gingival regions, the advantage is that it is painless, non-invasive, allows easy application of the formulation, and it is capable of avoiding the need of drug swallowing by the patient, a matter of relevance for children and the elderly. Another advantage is the high permeability of the oral mucosa, which may deliver very high amounts of medication rapidly to the bloodstream without significant damage to the stomach. This route also allows the local treatment of lesions that affect the oral cavity, as an alternative to systemic approaches involving injection-based methods and oral medications that require drug swallowing. Thus, this drug delivery route has been arousing great interest in the pharmaceutical industry. This review aims to condense information on the types of biomaterials and polymers used for this functionality, as well as on production methods and market perspectives of this topical drug delivery route

Immobilisation of apatite on Ti30Ta alloy surface by electrospinning of PCL

Surface modifications of titanium alloy have been extensively researched for the purpose of increasing the biocompatibility of medical implants. In this study, a Ti30Ta alloy surface was modified by functionalisation with electrospun poly(ε-caprolactone) (PCL) followed by the immobilisation of apatite (AP) to achieve a bioactive surface. Human adipose-derived stem cells were then cultured on the surfaces for up to 7 d to ensure the effects of PCL and AP treatments on cytocompatibility and cellular fate processes. PCL fibres and alloy surfaces were evaluated with scanning electron microscopy, X-ray diffraction and thermal analysis techniques. The analyses showed a uniform deposition of the electrospun PCL fibres on the entire Ti30Ta alloy surface. In addition, increases in cell growth and proliferation were seen after 7 d. Results indicated that the surface treatment of the Ti30Ta alloy with electrospun fibres and AP immobilisation may increase the bioactivity of the surface and provide a beneficial surface modification for use in biomedical applications52687

Surface modification of Ti-30Ta alloy by electrospun PCL deposition

In this study, PCL electrospun fibers were deposited on the Ti-30Ta alloy for change the surface properties. Experimental Ti-30Ta alloy was obtained by melting titanium and tantalum in arc melting furnace with argon atmosphere. Ingots were homogenized and bars with 10 mm of diameter were obtained in rotative swagging. PCL fibers were deposited on disks of the alloy by electrospinning. Plasma treatment was carried out for change PCL electrospun superficial energy by using stainless steel plasma reactor. Samples were immersed in mineralization solution for apatite growth. Surfaces were evaluated by using SEM, X-rays diffraction and contact angle. Samples exhibited hydrophilic behavior after plasma treatment and mineralization. Results are very interesting for biomedical applications869930934CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPNão temNão te

Terbinafine Nanohybrid: Proposing a Hydrogel Carrying Nanoparticles for Topical Release

A poloxamer 407 (P407)—Casein hydrogel was chosen to carry polycaprolactone nanoparticles carrying terbinafine (PCL-TBH-NP). In this study, terbinafine hydrochloride (TBH) was encapsulated into polycaprolactone (PCL) nanoparticles, which were further incorporated into a poloxamercasein hydrogel in a different addition order to evaluate the effect of gel formation. Nanoparticles were prepared by the nanoprecipitation technique and characterized by evaluating their physicochemical characteristics and morphology. The nanoparticles had a mean diameter of 196.7 0.7 nm, PDI of 0.07, negative potential (0.713 mV), high encapsulation efficiency (>98%), and did not show cytotoxic effects in primary human keratinocytes. PCL-NP modulated terbinafine was released in artificial sweat. Rheological properties were analyzed by temperature sweep tests at different addition orders of nanoparticles into hydrogel formation. The rheological behavior of nanohybrid hydrogels showed the influence of TBH-PCL nanoparticles addition in the mechanical properties of the hydrogel and a long-term release of the nanoparticles from it

Molecularly Imprinted Membrane Produced by Electrospinning for β-Caryophyllene Extraction

Molecularly imprinted membrane of β-caryophyllene (MIM–βCP) was fabricated incorporating β-caryophyllene molecularly imprinted polymer nanoparticles (βCP–NP) into polycaprolactone (PCL) fibers via electrospinning. The βCP–NP were synthesized by precipitation polymerization using the βCP as a template molecule and acrylic acid as a functional monomer in the proportion of 1:4 mol, respectively. Atomic force microscopy images and X-ray diffraction confirmed the nanoparticles’ incorporation into MIM–βCP. MIM–βCP functionalization was evaluated by gas chromatography. The binding capacity was 1.80 ± 0.05 μmol/cm2, and the selectivity test was performed with a mixing solution of βCP and caryophyllene oxide, as an analog compound, that extracted 77% of the βCP in 5 min. The electrospun MIM–βCP can be used to detect and extract the βCP, applications in the molecular sieve, and biosensor production and may also contribute as an initial methodology to enhance versatile applications in the future, such as in the treatment of skin diseases, filters for extraction, and detection of βCP to prevent counterfeiting of commercial products, and smart clothing with insect-repellent properties

Virucidal PVP-Copper Salt Composites against Coronavirus Produced by Electrospinning and Electrospraying

Electrospinning technology was used to produced polyvinylpyrrolidone (PVP)-copper salt composites with structural differences, and their virucidal activity against coronavirus was investigated. The solutions were prepared with 20, 13.3, 10, and 6.6% w/v PVP containing 3, 1.0, 0.6, and 0.2% w/v Cu (II), respectively. The rheological properties and electrical conductivity contributing to the formation of the morphologies of the composite materials were observed by scanning electron microscopy (SEM). SEM images revealed the formation of electrospun PVP-copper salt ultrafine composite fibers (0.80 ± 0.35 µm) and electrosprayed PVP-copper salt composite microparticles (1.50 ± 0.70 µm). Energy-dispersive X-ray spectroscopy (EDS) evidenced the incorporation of copper into the produced composite materials. IR spectra confirmed the chemical composition and showed an interaction of Cu (II) ions with oxygen in the PVP resonant ring. Virucidal composite fibers inactivated 99.999% of coronavirus within 5 min of contact time, with moderate cytotoxicity to L929 cells, whereas the virucidal composite microparticles presented with a virucidal efficiency of 99.999% within 1440 min of exposure, with low cytotoxicity to L929 cells (mouse fibroblast). This produced virucidal composite materials have the potential to be applied in respirators, personal protective equipment, self-cleaning surfaces, and to fabric coat personal protective equipment against SARS-CoV-2, viral outbreaks, or pandemics