Osteointegration on HA-Coated Carbon Fiber Composite Hip Stems

Peer reviewed: YesNRC publication: Ye

CaP coating on PEEK Varies upon Processing Conditions

Peer reviewed: YesNRC publication: Ye

Novel carbon fiber composite for hip replacement with improved in vitro and in vivo osseointegration

Peer reviewed: YesNRC publication: Ye

Enhanced proliferation and growth of non-differentiated and osteoblast-differentiated human stem cells on the surface of HVOF-sprayed nano TiO\u2082-HA coatings

Peer reviewed: YesNRC publication: Ye

Assessment of the biocompatibility of nanostructured polymeric fibers

Materials and methods -- Biocompatibility of novel polymer-apatite nanocomposite fibers -- Sterilization effects on bioactive polymer-apatite nanocomposite fibers

Biocompatibility of novel polymer-apatite nanocomposite fibers

On the basis of the bioactivity of hydroxyapatite (HA) and the excellent mechanical and biocompatible performance of polyethylene terephthalate (PET), composite microfibers made of nanograde HA with PET was designed and fabricated to mimic the structure of biological bone, which exhibits a composite of nanograde apatite crystals and natural polymer. The PET/HA nanocomposite was molded into fibers so that the bulk structures\u2019 mechanical properties can be custom tailored by changing the final 3D orientation of the fibbers. This study focused on the in vitro biocompatibility evaluation of the PET/HA composite fibers as potential bone fixation biomaterial for total hip replacement prosthesis surfaces. The MTT assay was performed with the extracts of the composite fibers in order to evaluate the short-term effects of the degradation products. The cell morphology of L929 mouse fibroblast cell line was analyzed after direct contact with the fiber scaffolds for different time periods, and the cell viability was also analyzed by the Alamar Blue assay. The release of the inflammatory cytokine, tumor necrosis factor-alpha (TNF-\u3b1), from RAW 264.7 macrophages in the presence of fiber extracts and fibers was used as a measure of the inflammatory response. The ability of the fiber matrices to support L929 attachment, spreading, and growth in vitro, combined with the compatible degradation extracts and low inflammation potential of the fibers and extracts, suggests potential use of these fibers as load-baring bone fixation biomaterial structures.Peer reviewed: YesNRC publication: Ye

Titania\u2013hydroxyapatite nanocomposite coatings support human mesenchymal stem cells osteogenic differentiation

In addition to mechanical and chemical stability, the third design goal of the ideal bone-implant coating is the ability to support osteogenic differentiation of mesenchymal stem cells (MSCs). Plasma-sprayed TiO \u2082-based bone-implant coatings exhibit excellent long-termmechanical properties, but their applications in bone implants are limited by their bioinertness. We have successfully produced a TiO \u2082 nanostructured (grain size <50 nm) based coating charged with 10% wt hydroxyapatite (TiO \u2082\u2013HA) sprayed by high-velocity oxy-fuel. On Ti64 substrates, the novel TiO \u2082\u2013HA coating bond 153x stronger and has a cohesive strength 4x higher than HA coatings. The HA microand nano-sized particles covering the TiO \u2082\u2013HA coating surface are chemically bound to the TiO2 coating matrix, producing chemically stable coatings under high mechanical solicitations. In this study, we elucidated the TiO \u2082\u2013HA nanocomposite coating surface chemistry, and in vitro osteoinductive potential by culturing human MSCs (hMSCs) in basal and in osteogenic medium (hMSC-ob). We assessed the following hMSCs and hMSC-ob parameters over a 3-week period: (i) proliferation; (ii) cytoskeleton organization and cell\u2013substrate adhesion; (iii) coating\u2013 cellular interaction morphology and growth; and (iv) cellular mineralization. The TiO2\u2013HA nanocomposite coatings demonstrated 3x higher hydrophilicity than HA coatings, a TiO2-nanostructured surface in addition to the chemically bound HA micron- and nano-sized rod to the surface. hMSCs and hMSC-ob demonstrated increased proliferation and osteoblastic differentiation on the nanostructured TiO \u2082\u2013HA coatings, suggesting the TiO \u2082\u2013HA coatings nanostructure surface properties induce osteogenic differentiation of hMSC and support hMSC-ob osteogenic potential better than our current golden standard HA coating.Peer reviewed: YesNRC publication: Ye

Low thrombogenicity coating of nonwoven PET fiber structures for vascular grafts

Vascular PET grafts (Dacron) have shown good performance in large vessels ( 656mm) applications. To address the urgent unmet need for small-diameter (2\u20136mm) vascular grafts, proprietary high-compliance nonwoven PET fiber structures were modified with various PEG concentrations using PVA as a cross-linking agent, to fabricate non-thrombogenicmechanically compliant vascular grafts. The blood compatibility assays measured through platelet adhesion (SEM and mepacrine dye) and platelet activation (morphological changes, P-selectin secretion, and TXB2 production) demonstrate that functionalization using a 10% PEG solution was sufficient to significantly reduce platelet adhesion/activation close to optimal literature-reported levels observed on carbon-coated ePTFE.Peer reviewed: YesNRC publication: Ye