Browsing by Author "Santos, Jerran"

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    Biocompatibility of a new biodegradable polymer-hydroxyapatite composite for biomedical applications
    (Elservier, 2017-04) Macha, Innocent J; Ben-Nissan, Besim; Santos, Jerran; Cazalbou, Sophie; Stamboulis, Artemis; Grossin, David; Giordano, Gerard
    The rise in the number of musculoskeletal disorders (MSDs) due to an increasingly aging population has led to a growing demand for medication to prevent and treat these diseases. An increased interest in the development of new drugs to allow treatment of these diseases in their very early stages is currently observed. The current approach on local direct delivery of medication and key minerals to support bone repair and regeneration at the defect site, from flexible degradable devices, seems to be an effective strategy. Polylactic acid (PLA) and microspheres of hydrothermally converted coralline hydroxyapatite (cHAp) were used to develop PLA thin film composites as drug delivery systems. The PLA provided flexibility and biodegradability of the systems, while coralline hydroxyapatite provided the required calcium and phosphate ions for bone regeneration. These coralline hydroxyapatite microspheres have a unique architecture of interconnected porosity, are bioactive in nature and suitable for drug loading and controlled slow drug release. The cell attachment and morphology of the PLA thin film composites were evaluated in vitro using cell cultures of human adipose derived stem cells (hADSC). It was shown that hADSC cells exhibited a strong attachment and proliferation on PLA thin film-cHAp composites, signifying high biocompatibility and a potential for osteointegration due to the presence of HAp.
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    Hydroxyapatite/PLA Biocomposite thin Films for Slow Drug Delivery of Antibiotics for the Treatment of Bone And Implant-Related Infections
    (2016-03) Macha, Innocent J; Ben-Nissan, Besim; Santos, Jerran; Cazalbou, Sophie; Milthorpe, Bruce K.
    rug delivery systems were developed from coralline hydroxyapatite (HAp) and biodegradable polylactic acid (PLA). Gentamicin (GM) was loaded in either directly to PLA (PLAGM) or in HAp microspheres. Drug loaded HAp was used to make thin film composites (PLAHApGM). Dissolution studies were carried out in phosphate buffered saline (PBS. The release profiles suggested that HAp particles improved drug stabilization and availability as well control the release rate. The release also displays a steady state release. In vitro studies in human Adipose Derived Stem Cells (hADSCs) showed substantial quantities of cells adhering to hydroxyapatite containing composites. The results suggested that the systems could be tailored to release different clinical active substances for a wide range of biomedical applications.
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    In vitro bioactivity and stem cells attachment of three-dimensionally ordered macroporous bioactive glass incorporating iron oxides
    (Elservier, 2016-11) Charoensuk, Thanida; Sirisathitkul, Chitnarong; Boonyang, Upsorn; Macha, Innocent J; Santos, Jerran; Grossin, David; Ben-Nissan, Besim
    Three-dimensionally ordered macroporous bioactive SiO2-CaO-Na2O-P2O5 glass (3DOM-BG) is synthesized by using the sol-gel method. After an in vitro test in simulated body fluid (SBF), the hydroxyapatite (HAp) crystalline phase is clearly formed on its surface as confirmed by X-ray diffractometry (XRD) and Raman spectroscopy. Magnetic 3DOM-BG/Fe samples are synthesized by partial substitution of SiO2 with iron oxide. Whilst the HAp layer is not confirmed, energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and XRD analysis reveal calcium phosphate layer on the surface of 3DOM-BG/Fe samples after the SBF soaking. The growth of HAp-like layer is slower with increasing iron oxides. The initial mechanism that thought to induce bone formation is reduced due to the replacement of Ca2 + with Fe ions in the glass network. The formation of HAp-like layer is modified by the sedimentation of Ca and P while the nonmagnetic 3DOM-BG forms the calcium phosphate by the ionic exchange following the Hench mechanism. The adult human adipose tissue-derived stem cells (hADSCs) can be closely attached and well spread on the flat-plate of all 3DOM-BG/Fe and 3DOM-BG. Without detectable cytotoxicity possibly induced by iron oxides, the osteoblast can be grown and proliferated. In addition to these bioactivity and biocompatibility, porous structures can allow their possible use in targeted drug delivery and magnetic properties of 3DOM-BG/Fe can essentially be implemented in hyperthermia therapy.