In this study, cross-linked activated organo-bentonite (AOBent)/sodium alginate (SA) composite was prepared by the intercalation of sodium alginate in activated organo-bentonite and the cross-linking ...reaction between sodium alginate and chlorhydric acid to produce interesting new low cost material for the removal of cationic and anionic dyes (methylene blue (MB) and methyl orange (MO)) from aqueous solutions. Adsorbents were characterized by using X-ray diffraction (XRD), thermal gravimetric analyses (TGA) and Fourier transform infrared spectroscopy (FTIR). Batch adsorption studies were carried out to evaluate the effect of pH solution, the kinetic and the isotherm on the adsorption capacity of the adsorbents. The kinetic of MB and MO adsorption was found to follow a pseudo-second-order kinetic model meanwhile the isotherm was well described by the Langmuir model for all samples. Results obtained from this study suggest the potential of prepared composites for cationic and anionic dyes removal which can also be used easily for clean and ecofriendly processes.
•An activated organo-bentonite–alginate (AOB/SA) composite was prepared facilely.•Pseudo-second-order kinetics was the most suitable adsorption model.•The isotherm model is in good agreement with Langmuir model.•The maximum monolayer adsorption capacity was 769mg/g for MB onto composite.•AOB/SA is an efficient adsorbent for the removal of anionic and cationic dyes.
Tendon disorders are common medical conditions, which can be greatly debilitating as they are often accompanied by great pain and inflammation. The techniques used nowadays for the treatment of ...chronic tendon injuries often involve surgery. However, one critical aspect of this procedure involves the scar tissue, characterized by mechanical properties that vary from healthy tissue, rendering the tendons inclined to reinjury or rupture. Synthetic polymers, such as thermoplastic polyurethane, are of special interest in the tissue engineering field as they allow the production of scaffolds with controlled elastic and mechanical properties, which could guarantee an effective support during the new tissue formation. The aim of this work was the design and the development of tubular nanofibrous scaffolds based on thermoplastic polyurethane and enriched with cerium oxide nanoparticles and chondroitin sulfate. The scaffolds were characterized by remarkable mechanical properties, especially when tubular aligned, reaching values comparable to the ones of the native tendons. A weight loss test was performed, suggesting a degradation in prolonged times. In particular, the scaffolds maintained their morphology and also remarkable mechanical properties after 12 weeks of degradation. The scaffolds promoted the cell adhesion and proliferation, in particular when in aligned conformation. Finally, the systems in vivo did not cause any inflammatory effect, representing interesting platforms for the regeneration of injured tendons.
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A combined approach based on drug complexation with cyclodextrins, and complex entrapment in nanoclays has been investigated, to join in a single delivery system the benefits of these ...carriers and potentiate their ability to improve the dissolution properties of oxaprozin (OXA), a poorly water-soluble anti-inflammatory drug. Based on previous studies, randomly methylated ß-cyclodextrin (RAMEB) was chosen as the most effective cyclodextrin for OXA complexation. Adsorption equilibrium studies performed on three different clays (sepiolite, attapulgite, bentonite) allowed selection of sepiolite (SV) for its greater adsorption power towards OXA. DSC and XRPD studies indicated drug amorphization in both binary OXA-RAMEB coground and OXA-SV cofused products, due to its complexation or very fine dispersion in the clay structure, respectively. The drug amorphous state was maintained also in the ternary OXA-RAMEB-SV cofused system. Dissolution studies evidenced a clear synergistic effect of RAMEB complexation and clay nanoencapsulation in improving the OXA dissolution properties, with an almost 100% increase in percent dissolved and dissolution efficiency compared to the OXA-RAMEB coground system. Therefore, the proposed combined approach represents an interesting tool for improving the therapeutic effectiveness of poorly soluble drugs, and reducing the CD amount necessary for obtaining the desired drug solubility and dissolution rate increase.
In recent decades, the demand for replacement of damaged or broken tissues has increased; this poses the attention on problems related to low donor availability. For this reason, researchers focused ...their attention on the field of tissue engineering, which allows the development of scaffolds able to mimic the tissues’ extracellular matrix. However, tissue replacement and regeneration are complex since scaffolds need to guarantee an adequate hierarchical structured morphology as well as adequate mechanical, chemical, and physical properties to stand the stresses and enhance the new tissue formation. For this purpose, the use of inorganic materials as fillers for the scaffolds has gained great interest in tissue engineering applications, due to their wide range of physicochemical properties as well as their capability to induce biological responses. However, some issues still need to be faced to improve their efficacy. This review focuses on the description of the most effective inorganic nanomaterials (clays, nano-based nanomaterials, metal oxides, metallic nanoparticles) used in tissue engineering and their properties. Particular attention has been devoted to their combination with scaffolds in a wide range of applications. In particular, skin, orthopaedic, and neural tissue engineering have been considered.
Exploration and production from formations deposited in low‐gradient fluvial systems is typically associated with a high degree of uncertainty; a reflection of the inherent characteristics of these ...environments, notably the dominance of non‐reservoir floodplain fines, rapid lateral facies variations and associated heterogeneities at different scales. However, for a field development to be successful it becomes crucial to know the location, geometry, dimensions and connectivity of the most permeable facies, related to the main channel and the associated proximal overbank deposits (crevasse‐splay complexes). With the aim of addressing this problem, a multi‐disciplinary study is presented, combining outcrop data, high‐resolution sedimentological descriptions and advanced visualization techniques based on Digital Outcrop Models. This is compared with subsurface data from behind the outcrop (core, gamma ray and borehole image logs). The Mudstone–Sandstone Unit of the Triassic Red Beds of Iberian Meseta formation in south‐central Spain was selected for the present study. The unit is characterized by the lateral and vertical stacking of four architectural elements: (i) channelized sandstone bodies; (ii) asymmetrical sigmoidal‐shaped sandstone bodies; (iii) lobe‐shaped to sheet‐like sandstone bodies; and (iv) sheet‐like mudstones. These elements represent meandering channel, crevasse‐channel‐splay and floodplain sub‐environments, comprising a distal, low‐gradient meandering fluvial system. Together with well‐documented outcrop and core facies, calibrated log responses are also presented for the channel bodies (bell‐shape Gamma Ray profile, random azimuths and low to high dip angles), the crevasse‐splay bodies (funnel‐shape Gamma Ray profile, unidirectional azimuths and low dip angles) and the floodplain deposits (serrated Gamma Ray profile, unidirectional azimuths and very low dip angles). The full integration of outcrop and subsurface datasets has enabled generation of a robust conceptual model with predictive potential when establishing the three‐dimensional stacking of facies, distribution of heterogeneities, and the connectivity between reservoir rock geobodies of primary (channel) and secondary (crevasse complex) interest in this type of fluvial reservoir.
Tendon disorders are common medical conditions that could lead to significant disability, pain, healthcare costs, and a loss of productivity. Traditional approaches require long periods of treatment, ...and they largely fail due to the tissues weakening and the postoperative alterations of the normal joint mechanics. To overcome these limitations, innovative strategies for the treatment of these injuries need to be explored. The aim of the present work was the design of nano-fibrous scaffolds based on poly(butyl cyanoacrylate) (PBCA), a well-known biodegradable and biocompatible synthetic polymer, doped with copper oxide nanoparticles and caseinphosphopeptides (CPP), able to mimic the hierarchical structure of the tendon and to improve the tissue healing potential. These were developed as implants to be sutured to reconstruct the tendons and the ligaments during surgery. PBCA was synthetized, and then electrospun to produce aligned nanofibers. The obtained scaffolds were characterized for their structure and physico-chemical and mechanical properties, highlighting that CuO and CPP loading, and the aligned conformation determined an increase in the scaffold mechanical performance. Furthermore, the scaffolds loaded with CuO showed antioxidant and anti-inflammatory properties. Moreover, human tenocytes adhesion and proliferation to the scaffolds were assessed in vitro. Finally, the antibacterial activity of the scaffolds was evaluated using
and
as representative of Gram-negative and Gram-positive bacteria, respectively, demonstrating that the CuO-doped scaffolds possessed a significant antimicrobial effect against
. In conclusion, scaffolds based on PBCA and doped with CuO and CPP deserve particular attention as enhancers of the tendon tissue regeneration and able to avoid bacterial adhesion. Further investigation on the scaffold efficacy in vivo will assess their capability for enhancing the tendon ECM restoration in view of accelerating their translation to the clinic.
Beads are versatile spherical drug delivery units that can be coated, filled into capsules or compressed as tablets to be orally administered. Crosslinking of chitosan (CS) and polyanions such as ...tripolyphosphate (TPP) results in beads with mechanical properties that could be improved by the addition of clay mineral particles to the bead network. Hybrid systems of palygorskite and chitosan have been shown to have advanced properties in biomedical applications as a result of the synergic effects of their combination. In this paper chitosan was intercalated with palygorskite (Pal) and the resultant hybrid was loaded with diclofenac, an anti-inflammatory drug. Chitosan (CS) beads crosslinked with sodium tripolyphosphate (TPP) were prepared and their properties compared to palygorskite/Chitosan (Pal/CS) beads. The synergic effects resulting from the clay/polymer hybrids were evaluated by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning transmission electron microscopy (SEM) and thermal analysis (thermogravimetric analysis, TGA, and differential scanning calorimetry, DSC). The results showed that chitosan and palygorskite interaction took place. Diclofenac sodium (DFNa) was used as model drug to reveal the effects of Pal within the bead structure. DFNa was successfully loaded into beads and FTIR analyses confirmed its presence. A drug release test was carried out in phosphate buffer medium (pH. 6.8). The results indicated that only 33% (w/w) of total drug was released from DFNa-Pal/CS compared to 66% (w/w) from DFNa-CS. The total amount of drug released fell significantly with the addition of palygorskite to the chitosan matrix. Pal/CS beads crosslinked with TPP were shown to be able of carrying diclofenac sodium, meaning they could possibly be used as drug carriers.
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•TPP crosslinked Palygorskite/Chitosan and Chitosan beads were synthesized.•Diclofenac sodium was successfully loaded into Pal/CS and CS beads.•Pal/CS is a promising material as carrier for drug delivery.
Nowadays the use of hydrogels for biomedical purposes is increasing because of their interesting features that allow the development of targeted drug delivery systems. Herein, hydrogel based on ...Laponite® (Lap) clay mineral as gelator and cucurbit6uril (CB6) molecules were synthetized for the delivery of flufenamic acid (FFA) for potential topical application. Firstly, the interaction between CB6 and FFA was assessed by UV‐vis spectroscopic measurements and molecular modeling calculations. Then, the obtained complex was used as filler for Lap hydrogel (Lap/CB6/FFA). The properties of the hydrogel in terms of viscosity and, self‐repair abilities were investigated; its morphology was imaged by scanning electron and polarized optical microscopies. Furthermore, the changes in the hydrodynamic radii and in the colloidal stability of CB6/Lap mixture were investigated in terms of translational diffusion from dynamic light scattering and ζ‐potential measurements. Finally, the kinetic in vitro release of FFA, from Lap/CB6/FFA hydrogel, was studied in a medium mimicking the pH of skin and the obtained results were discussed both by an experimental point of view and by molecular modeling calculations.
The use of hydrogels for biomedical purposes is increasing because of their interesting features that allow the development of targeted drug delivery systems. Herein, hydrogel based on Laponite® (Lap) clay mineral as gelator and cucurbit6uril (CB6) molecules were synthetized for the delivery of flufenamic acid (FFA) for potential topical application.
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