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Polymers have the potential to replace metallic or bioprosthetic heart valve components due to superior durability and inertness while allowing for native tissue-like flexibility. Despite these appealing properties, certain polymers such as polyetheretherketone (PEEK) have issues with hemocompatibility, which have previously been addressed through assorted complex processes. In this paper, we explore the enhancement of PEEK hemocompatibility with polymer crystallinity. Amorphous, semi-crystalline and crystalline PEEK are investigated in addition to a highly crystalline carbon fiber (CF)/PEEK composite material (CFPEEK). The functional group density of the PEEK samples is determined, showing that higher crystallinity results in increased amount of surface carbonyl functional groups. The increase of crystallinity (and negatively charged groups) appears to cause significant reductions in platelet adhesion (33 vs. 1.5% surface coverage), hemolysis (1.55 vs. 0.75%∙cm−2), and thrombin generation rate (4840 vs. 1585 mU/mL/min/cm2). In combination with the hemocompatibility study, mechanical characterization demonstrates that tailoring crystallinity is a simple and effective method to control both hemocompatibility and mechanical performance of PEEK. Furthermore, the results display that CFPEEK composite performed very well in all categories due to its enhanced crystallinity and complete carbon encapsulation, allowing the unique properties of CFPEEK to empower new concepts in cardiovascular device design., Biomaterials Advances, 146, ISSN:2772-9508

The association of an active principle with a nanocarrier is known to improve its stability and protect it from external factors. Nevertheless, loading of nanoparticles with highly hydrophilic substances like caffeine remains a tricky issue. In the present study, inverse miniemulsion systems were successfully coupled to UV radiation to synthesize polymeric nanohydrogels for drug delivery. The proper choice of the continuous and dispersed phase chemical composition led to the entrapment of active principle into the miniemulsion droplets. Our confinement-based strategy enabled unprecedented caffeine encapsulation efficiency inside 100-nm particles. Dimensional, thermal, and spectroscopic characterizations were carried out to investigate both unloaded and loaded nanohydrogels. Furthermore, in vitro release studies evaluated caffeine release kinetics from nanohydrogels by means of dialysis tests. It was demonstrated that controlled and sustained release occurred within the first 50 hours. Experimental data were found to fit the Higuchi model suggesting that the active principle release is diffusion controlled.

Cement composites were realized containing graphene-based materials having different oxygen content (from 0 to 45%). It was found that the polarity of the reinforcement influences both the dispersion in water and the chemical interaction with the hydrated cement matrix, and thus the mechanical performance of the composites. In particular, the reinforcements with the highest oxygen content result aggregated while the cement with the highest strength is obtained with functionalized graphene, containing 5% oxygen, where the surface has sufficient polar groups to guarantee proper dispersion and interaction with the hydrated cement.

In the field of pharmaceutical technology, significant attention has been paid on exploiting skin as a drug administration route. Considering the structural and chemical complexity of the skin barrier, many research works focused on developing an innovative way to enhance skin drug permeation. In this context, a new class of materials called bio-functional textiles has been developed. Such materials consist of the combination of advanced pharmaceutical carriers with textile materials. Therefore, they own the possibility of providing a wearable platform for continuous and controlled drug release. Notwithstanding the great potential of these materials, their large-scale application still faces some challenges. The present review provides a state-of-the-art perspective on the bio-functional textile technology analyzing the several issues involved. Firstly, the skin physiology, together with the dermatological delivery strategy, is keenly described in order to provide an overview of the problems tackled by bio-functional textiles technology. Secondly, an overview of the main dermatological nanocarriers is provided; thereafter the application of these nanomaterial to textiles is presented. Finally, the bio-functional textile technology is framed in the context of the different dermatological administration strategies; a comparative analysis that also considers how pharmaceutical regulation is conducted.

In recent years, the textile industry has been moving to novel concepts of products, which could deliver to the user, improved performances. Such smart textiles have been proven to have the potential to integrate within a commodity garment advanced feature and functional properties of different kinds. Among those functionalities, considerable interest has been played in functionalizing commodity garments in order to make them positively interact with the human body and therefore being beneficial to the user health. This kind of functionalization generally exploits biopolymers, a class of materials that possess peculiar properties such as biocompatibility and biodegradability that make them suitable for bio-functional textile production. In the context of biopolymer chitosan has been proved to be an excellent potential candidate for this kind of application given its abundant availability and its chemical properties that it positively interacts with biological tissue. Notwithstanding the high potential of chitosan-based technologies in the textile sectors, several issues limit the large-scale production of such innovative garments. In facts the morphologies of chitosan structures should be optimized in order to make them better exploit the biological activity; moreover a suitable process for the application of chitosan structures to the textile must be designed. The application process should indeed not only allow an effective and durable fixation of chitosan to textile but also comply with environmental rules concerning pollution emission and utilization of harmful substances.

The textile industry has recently been developing innovative products that integrate functional properties within commodity textiles. In particular, research has focussed on the concept of biofunctional textiles, i.e., textile materials possessing beneficial properties for human health. Biofunctional textiles are synthesised by functionalization of fabric surfaces with biopolymers. As an example, the chitosan biopolymer is promising for textile functionalization due to chitosan availability, low cost, safety and unique properties. Yet several challenges have to be overcome. Firstly, the morphology of chitosan must be optimized prior chitosan application to the textile surface. Secondly, the last treatment must be carefully designed in order to achieve an effective and durable functionalization. Lastly, the overall production process must comply with environmental rules concerning pollution emission and utilization of harmful substances. This review describes microencapsulation as a strategy to overcome limitations and to confer better properties to the textile material. The properties of chitosan and the concept of microencapsulation are presented. Then we present the main techniques of chitosan encapsulation. Furthermore, we detail the textile finishing processes and the textile products. Last, the perspectives are discussed in the context of green chemistry and compliance with an environmentally friendly approach.

Flash nanoprecipitation (FNP) is a widely used technique to prepare particulate carriers based on various polymers, and it was proven to be a promising technology for the industrial production of drug loaded nanoparticles. However, up to now, only its application to hydrophobic compounds has been deeply studied and the encapsulation of some strongly hydrophilic compounds, such as caffeine, remains a challenge. Caffeine loaded poly-&epsilon, caprolactone (PCL) nanoparticles were produced in a confined impinging jet mixer using acetone as the solvent and water as the antisolvent. Caffeine was dissolved either in acetone or in water to assess the effects of two different process conditions. Nanoparticles properties were assessed in terms of loading capacity (LC%), encapsulation efficiency (EE%), and in vitro release kinetics. Samples were further characterized by dynamic light scattering, scanning electron microscopy, X-ray photo electron spectroscopy, and infrared spectroscopy to determine the size, morphology, and structure of nanoparticles. FNP was proved an effective technique for entrapping caffeine in PCL and to control its release behavior. The solvent used to solubilize caffeine influences the final structure of the obtained particles. It was observed that the active principle was preferentially adsorbed at the surface when using acetone, while with water, it was embedded in the matrix structure. The present research highlights the possibility of extending the range of applications of FNP to hydrophilic molecules.

Bioinspiration can lead to exceptional mechanical properties in a number of biological materials as a result of their internal structure. In particular, the hierarchical arrangement of nano-to macro-components can bring to complex energy dissipation mechanisms and unprecedented resistance to crack growth. In this work, we propose to exploit this approach, combining in a multiscale composite structure carbon nanotubes with conventional carbon fibre reinforcements in a polyvinyl butyral matrix. We show that grafting the nanotubes onto the carbon microfibres improves their interface properties with the matrix considerably, effectively doubling their apparent strength. At the same time, the addition of nanotubes to microfibre reinforcements helps to improve the composite toughness, reaching more than twice the value for the conventional, non-hierarchically reinforced composite. Numerical simulations and fracture mechanics considerations are also provided to interpret the results.

In recent years transdermal drug delivery has aroused significant interest as a sustained and non-invasive way of administering active substances. The advancements of nanotechnology allowed the development of novel pharmaceutical formulations overcoming skin barrier. Furthermore, such nano-system can be combined with conventional fabrics to pave the way to a new generation of wearable drug delivery devices: bio-functional garments. First the NP were produced by flash nanoprecipitation technique (FNP), the production process was optimized to produce particles with suitable size for transdermal applications. The nanoparticles were characterized in terms of drug content by UV-visible spectroscopy and in term of antioxidant activity by Electron Paramagnetic Resonance spectroscopy (EPR) coupled with spin trapping technique. The NPs were used to functionalize cotton and viscose-micromodal fabrics and the transdermal release properties were tested in vitro by Franz's Cell experiment. FNP was proven to be an effective technique to produce tunable size particles. Moreover, the nanoencapsulated drug exhibited antioxidant activity. The Franz's Cell test evidenced a controlled release behavior, providing evidence that the bio-functional textile is suitable for applications where sustained release and antioxidant properties are required.

Drug delivery by means of transdermal patches raised great interest as a non-invasive and sustained therapy. The present research aimed to design a patch for transdermal delivery of melatonin, which was encapsulated in polycaprolactone (PCL) nanoparticles (NPs) by employing flash nanoprecipitation (FNP) technique. Melatonin-loaded PCL nanoparticles were successfully prepared with precise control of the particle size by effectively tuning process parameters. The effect of process parameters on the particle size was assessed by dynamic light scattering for producing particles with suitable size for transdermal applications. Quantification of encapsulated melatonin was performed by mean of UV spectrophotometry, obtaining the estimation of encapsulation efficiency (EE%) and loading capacity (LC%). An EE% higher than 80% was obtained. Differential scanning calorimetry (DSC) analysis of NPs was performed to confirm effective encapsulation in the solid phase. Cotton fabrics, functionalized by imbibition with the nano-suspension, were analyzed by scanning electron microscopy to check morphology, adhesion and distribution of the NPs on the surface; melatonin transdermal release from the functionalized fabric was performed via Franz’s cells by using a synthetic membrane. NPs were uniformly distributed on cotton fibres, as confirmed by SEM observations; the release test showed a continuous and controlled release whose kinetics were satisfactorily described by Baker–Lonsdale model.