Structure and properties of biodegradable wheat gluten/attapulgite nanocomposite sheets

Antitumor Efficacy of Doxorubicin-Loaded Electrospun Attapulgite–Poly(lactic-co-glycolic acid) Composite Nanofibers

Currently, cancer chemotherapeutic drugs still have the defects of high toxicity and low bioavailability, so it is critical to design novel drug release systems for cancer chemotherapy. Here, we report a method to fabricate electrospun drug-loaded organic/inorganic hybrid nanofibrous system for antitumor therapy applications. In this work, rod-like attapulgite (ATT) was utilized to load a model anticancer drug doxorubicin (DOX), and mixed with poly(lactic-co-glycolic acid) (PLGA) to form electrospun hybrid nanofibers. The ATT/DOX/PLGA composite nanofibers were characterized through various techniques. It is feasible to load DOX onto ATT surfaces, and the ATT/DOX/PLGA nanofibers show a smooth and uniform morphology with improved mechanical durability. Under neutral and acidic pH conditions, the loaded DOX was released from ATT/DOX/PLGA nanofibers in a sustained manner. In addition, the released DOX from the nanofibers could significantly inhibit the growth of tumor cells. Owing to the significantly reduced burst release profile and increased mechanical durability of the ATT/DOX/PLGA nanofibers, the designed organic–inorganic hybrid nanofibers may hold great promise as a nanoplatform to encapsulate different drugs for enhanced local tumor therapy applications.

3D printed biocompatible graphene oxide, attapulgite, and collagen composite scaffolds for bone regeneration

Tissue-engineered bone material is one of the effective methods to repair bone defects, but the application is restricted in clinical because of the lack of excellent scaffolds that can induce bone regeneration as well as the difficulty in making scaffolds with personalized structures. 3D printing is an emerging technology that can fabricate bespoke 3D scaffolds with precise structure. However, it is challenging to develop the scaffold materials with excellent printability, osteogenesis ability, and mechanical strength. In this study, graphene oxide (GO), attapulgite (ATP), type I collagen (Col I) and polyvinyl alcohol were used as raw materials to prepare composite scaffolds via 3D bioprinting. The composite materials showed excellent printability. The microcosmic architecture and properties was characterized by scanning electron microscopy, Fourier transform infrared and thermal gravimetric analyzer, respectively. To verify the biocompatibility of the scaffolds, the viability, proliferation and osteogenic differentiation of Bone Marrow Stromal Cells (BMSCs) on the scaffolds were assessed by CCK-8, Live/Dead staining and Real-time PCR in vitro. The composited scaffolds were then implanted into the skull defects on rat for bone regeneration. Hematoxylin-eosin staining, Masson staining and immunohistochemistry staining were carried out in vivo to evaluate the regeneration of bone tissue.The results showed that GO/ATP/COL scaffolds have been demonstrated to possess controlled porosity, water absorption, biodegradability and good apatite-mineralization ability. The scaffold consisting of 0.5% GO/ATP/COL have excellent biocompatibility and was able to promote the growth, proliferation and osteogenic differentiation of mouse BMSCs in vitro. Furthermore, the 0.5% GO/ATP/COL scaffolds were also able to promote bone regeneration of in rat skull defects. Our results illustrated that the 3D printed GO/ATP/COL composite scaffolds have good mechanical properties, excellent cytocompatibility for enhanced mouse BMSCs adhesion, proliferation, and osteogenic differentiation. All these advantages made it potential as a promising biomaterial for osteogenic reconstruction.

Functional Nanocomposites Based on Fibrous Clays

This chapter is focused on functional nanocomposites based on the use of the microfibrous clays sepiolite and palygorskite as efficient fillers for diverse types of polymer matrices, from typical thermoplastics to biopolymers. The main features that govern the interaction between the silicates and the polymer matrix are discussed. The introduction addresses the structural and textural features of the fibrous silicates, as well as the possible synthetic approaches to increase the compatibility of these nanofillers with the polymeric matrix. Additionally, these clays can be easily functionalized through their surface silanol groups based on chemical reactions or by anchoring of nanoparticles. This allows for the preparation of a wide variety of functional polymer–clay nanocomposites. Thereafter, some relevant examples of nanocomposites derived from conventional polymers are reported, as well as of those based on polymers that exhibit electrical conductivity. Lastly, selected works employing sepiolite or palygorskite as fillers in polymeric matrixes of natural origin are discussed, showing the wide application of these resulting nanocomposites as bioplastics, as well as in biomedicine, environmental remediation and the development of sensor devices.

A facile approach for the fabrication of nano-attapulgite/poly(vinyl pyrrolidone)/biopolymers core–sheath ultrafine fibrous mats for drug controlled release

Herein, we report a facile method for the fabrication of flurbiprofen axetil (FA)-loaded core–sheath composite ultrafine fibers for drug sustained release.

Attapulgite-doped electrospun poly(lactic-co-glycolic acid) nanofibers enable enhanced osteogenic differentiation of human mesenchymal stem cells

Attapulgite-doped electrospun poly(lactic-co-glycolic acid) nanofibers enable enhanced osteogenic differentiation of human mesenchymal stem cells.