Rupak Dua

Bio: Rupak Dua is an academic researcher from Hampton University. The author has contributed to research in topics: Cartilage & Surface modification. The author has an hindex of 8, co-authored 17 publications receiving 332 citations. Previous affiliations of Rupak Dua include Florida International University & International University, Cambodia.

Graphene nanoplatelet-induced strengthening of ultrahigh molecular weight polyethylene and biocompatibility in vitro.

Abstract: Graphene nanoplatelets (GNPs) are added as reinforcement to ultrahigh molecular weight polyethylene (UHMWPE) with an intended application for orthopedic implants. Electrostatic spraying is established as a potential fabrication method for synthesizing large-scale UHMWPE-GNP composite films. At a low concentration of 0.1 wt % GNP, the composite film shows highest improvement in fracture toughness (54%) and tensile strength (71%) as compared to UHMWPE. Increased GNP content of 1 wt % leads to improvement in elastic modulus and yield strength but fracture toughness and tensile strength are reduced significantly at higher GNP content. The strengthening mechanisms of the UHMWPE-GNP system are highly influenced by the GNP concentration, which dictates its degree of dispersion and extent of polymer wrapping. The fraction of GNPs oriented along the tensile axis influences the elastic deformation, whereas the wrapping of polymer and GNP-polymer interfacial strength determines the deformation behavior in the plastic regime. The cytotoxicity of GNP to osteoblast is dependent on its concentration and is also influenced by agglomeration of particles. Lowering the concentration of GNPs in UHMWPE improves the biocompatibility of the composite surface to bone cells. The survivability of osteoblasts deteriorates up to 86% on 1 wt % GNP containing surface, whereas much smaller (6-16%) reduction is observed for 0.1 wt % GNP over 5 days of incubation.

Three Dimensional Graphene Foam/Polymer Hybrid as a High Strength Biocompatible Scaffold

Abstract: Graphene foam (GrF)/polylactic acid–poly-e-caprolactone copolymer (PLC) hybrid (GrF-PLC) scaffold is synthesized in order to utilize both the desirable properties of graphene and that of foams such as excellent structural characteristics and a networked 3-D structure for cells to proliferate in. The hybrid scaffold is synthesized by a dip-coating method that enables retention of the porous 3D structure. The excellent wettability of PLC with graphene foam along with the formation of PLC bridges leads to a ≈3700% enhancement in strength and a ≈3100% increase in ductility in the GrF-PLC scaffold. Biocompatibility of both graphene foam and GrF-PLC scaffold is demonstrated by culturing of human mesenchymal stem cells (hMSCs) for 28 days, a period over which cell proliferation is robust. The hMSCs are differentiated in chondrogenic media and supported chondrogenesis in both scaffolds. The demand for aggrecan extracellular matrix protein synthesis is reduced in hybrids due to improved bearing of cell-induced loads, this may be critical for ensuring adequate cellular distribution and layering of extracellular matrix. Hence, the unique mechanical and biotolerant properties of the GrF-PLC scaffold are suited for musculoskeletal tissue engineering applications, such as the growth of de novo cartilage to replace cartilage lost due to injury or osteoarthritis.

Applications of 3D-Printed PEEK via Fused Filament Fabrication: A Systematic Review

Abstract: Polyether ether ketone (PEEK) is an organic polymer that has excellent mechanical, chemical properties and can be additively manufactured (3D-printed) with ease. The use of 3D-printed PEEK has been growing in many fields. This article systematically reviews the current status of 3D-printed PEEK that has been used in various areas, including medical, chemical, aerospace, and electronics. A search of the use of 3D-printed PEEK articles published until September 2021 in various fields was performed using various databases. After reviewing the articles, and those which matched the inclusion criteria set for this systematic review, we found that the printing of PEEK is mainly performed by fused filament fabrication (FFF) or fused deposition modeling (FDM) printers. Based on the results of this systematic review, it was concluded that PEEK is a versatile material, and 3D-printed PEEK is finding applications in numerous industries. However, most of the applications are still in the research phase. Still, given how the research on PEEK is progressing and its additive manufacturing, it will soon be commercialized for many applications in numerous industries.

Corrosion and Biocompatibility Assessment of Magnesium Alloys

Abstract: Magnesium due to its good biocompatibility, mechanical properties, necessity in metabolic processes and lightness in weight, is an ideal candidate for biodegradable implants. The major concerns with magnesium and its alloys are that of rapid and non-uniform corrosion. In this investigation, magnesium based binary, ternary and quaternary alloys were studied for their corrosion resistance and biocompatibility. In vitro corrosion resistance of the alloys was studied in accordance with ASTM G 102-89in phosphate buffered saline (PBS) at 37°C. The surface morphology of the alloys was studied using scanning electron microscopy (SEM) and the wettability of the alloys was determined by contact angle measurements. Additionally, the cytotoxicity of the leached metal ions on the viability of osteoblast was evaluated bysulforhodamine B (SRB) assay.

Promises, facts and challenges for graphene in biomedical applications

Abstract: The graphene family has captured the interest and the imagination of an increasing number of scientists working in different fields, ranging from composites to flexible electronics. In the area of biomedical applications, graphene is especially involved in drug delivery, biosensing and tissue engineering, with strong contributions to the whole nanomedicine area. Besides the interesting results obtained so far and the evident success, there are still many problems to solve, on the way to the manufacturing of biomedical devices, including the lack of standardization in the production of the graphene family members. Control of lateral size, aggregation state (single vs. few layers) and oxidation state (unmodified graphene vs. oxidized graphenes) is essential for the translation of this material into clinical assays. In this Tutorial Review we critically describe the latest developments of the graphene family materials into the biomedical field. We analyze graphene-based devices starting from graphene synthetic strategies, functionalization and processibility protocols up to the final in vitro and in vivo applications. We also address the toxicological impact and the limitations in translating graphene materials into advanced clinical tools. Finally, new trends and guidelines for future developments are presented.

Functional Graphene Nanomaterials Based Architectures: Biointeractions, Fabrications, and Emerging Biological Applications

Abstract: Functional graphene nanomaterials (FGNs) are fast emerging materials with extremely unique physical and chemical properties and physiological ability to interfere and/or interact with bioorganisms; as a result, FGNs present manifold possibilities for diverse biological applications. Beyond their use in drug/gene delivery, phototherapy, and bioimaging, recent studies have revealed that FGNs can significantly promote interfacial biointeractions, in particular, with proteins, mammalian cells/stem cells, and microbials. FGNs can adsorb and concentrate nutrition factors including proteins from physiological media. This accelerates the formation of extracellular matrix, which eventually promotes cell colonization by providing a more beneficial microenvironment for cell adhesion and growth. Furthermore, FGNs can also interact with cocultured cells by physical or chemical stimulation, which significantly mediate their cellular signaling and biological performance. In this review, we elucidate FGNs–bioorganism int...