Ahydrothermalsynthesisofeggshellandfruitwasteextra

CERAMICSINTERNATIONALAvailableonlineat](]]]])]]]–]]]AhydrothermalsynthesisofeggshellandfruitwasteextracttoproducenanosizedhydroxyapatiteShih-ChingWua,b,Hsi-KaiTsouc,Hsueh-ChuanHsua,b,Shih-KuangHsua,b,Shu-PingLioud,Wen-FuHoe,naDepartmentofDentalTechnologyandMaterialsScience,CentralTaiwanUniversityofScienceandTechnology,Taiwan,ROCbInstituteofBiomedicalEngineeringandMaterialsScience,CentralTaiwanUniversityofScienceandTechnology,Taiwan,ROCcDepartmentofNeurosurgery,TaichungVeteransGeneralHospital,Taichung,Taiwan,ROCdDepartmentofMechanicalandAutomationEngineering,Da-YehUniversity,Taiwan,ROCeAdvancedMaterialsandBioMaterialsLab,DepartmentofMaterialsScienceandEngineering,Da-YehUniversity,Taiwan,ROCReceived20March2013;receivedinrevisedform29March2013;accepted30March2013AbstractEggshellsaretypicallyconsideredtobegarbagebecausetheyhavenovalueasfoodbuttheyfavormicrobialgrowth.Vastquantitiesofeggshellwasteareavailablefromfoodprocessing,baking,andhatchingindustries.Thepresentstudyprovidesasimplehydrothermalmethodtoobtainhigh-purityhydroxyapatite(HA)nanoparticlesfromeggshellsandthreekindsoffruitwasteextracts:grape,sweetpotato,andpomelopeels.ThesesynthesizednanoparticleshavebeencharacterizedbyX-raydiffraction,Fouriertransforminfraredspectroscopy,andscanningelectronmicroscopystudies.Theresultsshowedthathydrothermalreactiontimesandbiomoleculeamountsinfluencedproductshape,productsize,andsyntheticHAcrystalmorphology.TheHAtakenfrompomelopeelingsexhibitedgoodaspectratioswithphysicalshapessimilartothoseofthecrystallineHAstructuresofnaturalhumanbone.HAsynthesizedfromeggshellpowderscontainsseveralimportanttraceelements,suchasNa,Mg,andSr.&2013ElsevierLtdandTechnaGroupS.r.l.Allrightsreserved.Keywords:Eggshell;Hydroxyapatite;Nanoparticles;Wastematerials;Hydrothermal1.IntroductionHydroxyapatite(HA)hasbeenwidelyusedasanimplantmaterialduetoitsclosesimilarityincompositiontonaturalbone.ManystudieshaveshownthatHAceramicsshownotoxicity,noinflammatoryresponse,nopyrogeneticresponse,nofibroustissueformationbetweenimplantandbone,andtheabilitytobonddirectlytothehostbone[1–3].ArtificialHAhasmanyapplications,suchasbonegraftsubstitutes,sustained-releasedrugdeliverydevices,andproteinpurifica-tion[4,5].However,themineralcompositionofhumanbonediffersslightlyfromstoichiometricHAduetotheimpuritiesinhumanbone,whichincludecarbonate,chloride,fluoride,magnesium,andsodium[6,7].Thenaturalapatiteofthehumanbodycontainsapproximately3–8wt%ofcarbonate[8].NaturalbonetissueincludestinyHAcrystalsinitsnano-regime[9].NanosizedHAexhibitsmuchhigherbioactivitythancoarsercrystals;nanophaseceramicsmadefromnanosizedHAmayhelposteoblaststosynthesizealkalinephosphatase.Suchceramicsmayalsopromotetheadhesionandproliferationofcellsandleadtorapidrepairofhardtissueinjuries[10].Overthepastseveralyears,biologicallyderivednaturalmaterialssuchasbovinebones[11],fishbones[12],oystershells[13],corals[14–16]andeggshells[17]havebeenconvertedintousefulbiomaterialslikeHA.BiologicalHAobtainedfromnaturalresourcespreservessomepropertiesoftheprecursormaterial,suchasporestructureandchemicalcomposition[18].In1974,RoyandLinnehan[14]simplifiedthefieldbytakingabiomimeticapproachthatemployedthedirectconversionofcoralcalciumcarbonateskeletonsintoHA://dx.doi.org/10.1016/j.ceramint.2013.03.094nCorrespondenceto:DepartmentofMaterialsScienceandEngineering,Da-YehUniversity,168UniversityRoad,Dacun,Changhua,Taiwan51591,ROC.Tel.:[phone]x4108;fax:[phone].E-mailaddresses:[e-mail],[e-mail](W.-F.Ho).Pleasecitethisarticleas:S.-C.Wu,etal.,Ahydrothermalsynthesisofeggshellandfruitwasteextracttoproducenanosizedhydroxyapatite,CeramicsInternational(2013),(termedcorallineHA).Sivakumaretal.[15]usedahydro-thermalprocesstoderiveHAfromcoralsfromtheGulfofMannar,offthecoastofIndia.HydrothermalconversionofAustraliancoralsintoHAwasstudiedbyHuetal.[16].However,somecoralspeciesareindangerofextinctionandmostcoralspecieshaveslowgrowthrates.Therefore,itisurgenttoexplorenewalternativematerialsthatarerenewable,low-priced,andeasilyaccessible.Avianeggshellhasamineralcompositionsimilartocorals.Eggshellshavebeenintroducedasacandidatematerialformaxillofacialandcraniofacialsurgerybecauseavianeggshellscanbeprocuredeasily[19,20].Fresheggshelltypicallyconsistsofathree-layeredstructure;thecuticleontheoutersurfaceresemblesaceramic;themiddlelayerisspongy;theinnerlayerconsistsoflamellarlayers.Theeggshellrepresentsapproximately11%ofthetotalweightofegg.Thechemicalcomposition(byweight)ofchickeneggshellconsistsofcalciumcarbonate(94%),magnesiumcarbonate(1%),calciumphosphate(1%),andorganicmatter(4%)[21].Chickeneggshellscontaintraceelements,suchasNa,Mg,andSr,whicharealsofoundinhumanbone.Chickeneggshellsthatwouldnormallybediscardedasgarbagecanbeusedashigh-qualitycalciumsourcesforthepreparationofHA;thisincidentallyeliminatesthecostofr