title: Hydroxyapatite formed on/in agarose gel induces activation of blood coagulation and platelets aggregation.
abstract: We reported earlier that hydroxyapatite (HA) formed on/in agarose gels (HA/agarose) produced by alternate soaking process is a bone-filling material possessing osteoconductive and hemostatic effects. This process could allow us to make bone-like apatite that was formed on/in organic polymer hydrogel matrices. Here, we investigated the mechanism of hemostasis induced by HA/agarose and found that HA/agarose, but not agarose or HA powder, significantly shortened activated partial thromboplastin time (APTT). While HA/agarose did not show significant platelet aggregation, it markedly enhanced adenosine diphosphate (ADP)-induced platelet aggregation. Moreover, Western blot analysis revealed selective adsorption of vitronectin onto HA/agarose. We also observed marked differences between HA powder and HA/agarose in their XRD patterns. The crystallinity of HA powder was much higher compared to that of HA/agarose. Furthermore, 50-100 nm of tube-form aggregations was observed in HA powder on the other hand 100-200 nm of particles was observed in HA/agarose by SEM observation. Thus 100-200 nm of low crystallized particles on the surface structure of HA/agarose may play an important role in hemostasis. Our results demonstrated a crucial role of HA/agarose in the mechanism of hemostasis and suggested a potential role for HA/agarose as a bone-grafting material.
authors.affiliation: Developmental Therapeutics Course, Oral and Maxillofacial Rehabilitation, Department of Maxillofacial Diagnostic and Surgical Science, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan.
authors.forename: Shin-ichiro
authors.initials: S
authors.lastname: Arimura
authors.forename: Ko-ichi
authors.initials: K
authors.lastname: Kawahara
authors.forename: Kamal Krishna
authors.initials: KK
authors.lastname: Biswas
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Abeyama
authors.forename: Masashi
authors.initials: M
authors.lastname: Tabata
authors.forename: Toru
authors.initials: T
authors.lastname: Shimoda
authors.forename: Daisuke
authors.initials: D
authors.lastname: Ogomi
authors.forename: Michiya
authors.initials: M
authors.lastname: Matsusaki
authors.forename: Shinya
authors.initials: S
authors.lastname: Kato
authors.forename: Takashi
authors.initials: T
authors.lastname: Ito
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Sugihara
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Akashi
authors.forename: Teruto
authors.initials: T
authors.lastname: Hashiguchi
authors.forename: Ikuro
authors.initials: I
authors.lastname: Maruyama
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000327:Adsorption; D001777:Blood Coagulation / Q000187:drug effects*; D018786:Bone Substitutes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D017886:Durapatite / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D005782:Gels; D006487:Hemostasis / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010314:Partial Thromboplastin Time; D010974:Platelet Aggregation / Q000187:drug effects*; D011208:Powders; D011517:Prothrombin Time; D012685:Sepharose; D013499:Surface Properties; D019096:Vitronectin / Q000493:pharmacokinetics; D014961:X-Ray Diffraction
chemical_list: D018786:Bone Substitutes; D005782:Gels; D011208:Powders; D019096:Vitronectin; D000244:Adenosine Diphosphate; D012685:Sepharose; D017886:Durapatite