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Preparation And Properties Of Biomedical Materials Based On Calcium Alginate

Posted on:2015-04-17Degree:DoctorType:Dissertation
Country:ChinaCandidate:Z Q LiFull Text:PDF
GTID:1314330518971552Subject:Materials science
Abstract/Summary:PDF Full Text Request
Natural polymer material sodium alginate has excellent biodegradablility,biocompatibility,good gel and film property,so calcium alginate matrix biomedical material prepared by sodium alginate have wide application prospect in medicine and biotechnology.In order to obtain various morphologies biological medical materials based on calcium alginate which are suitable for different fields,in this paper we prepare microspheres,microcapsules and membranes based on calcium alginate by three different methods,respectively.Then research the performance of three morphologies of calcium alginate matrix biomedical material systematically.First of all,calcium alginate microspheres have been manufactured by dripping method.By choosing solution concentration,flow rate,the distance between the orifice tip and surface of the cross-linking solution and drying methods which affect shape of calcium alginate microspheres to get good shape microspheres.Research shows that:the optimum conditions to obtain calcium alginate microspheres with good sphericity is that the concentration of sodium alginate is 1.5wt%?2.5wt%,the sample rate is 1ml/min,dropping distance is 8cm,and best calcification time is 30min.the calcium alginate microspheres prepared by anhydrous ethanol dehydration have the best spherical degree,swelling ratio and the fastest release rate of bovine serum albumin.Secondly,this paper design and prepare developable silver nanoparticle/calcium alginate embolic microspheres and developable meglumine diatrizoate/calcium alginate embolic microspheres with the optimum process.Synthesis of silver nanoparticles by chemical reduction method,through the investigation of stabilizer concentration,reducing agent dosage and reaction time effects on the generation of silver nanoparticles,determine the optimum conditions process parameters for preparation of silver nanoparticles are molar ratio of sodium alginate with silver nitrate as 2.5:1,sodium borohydride and silver nitrate molar ratio 1:1,reaction time 30 minutes.Prepare developable meglumine diatrizoate/calcium alginate embolic microspheres and developable silver nanoparticle/calcium alginate embolic microspheres under the optimum conditions.The results show that:the two kinds of microspheres are visible in X-rays.When meglumine diatrizoate and water volume ratio is greater than 4:6,meglumine diatrizoate calcium alginate microspheres have the enhancement effect,but when the meglumine diatrizoate and water volume ratio is greater than 5:5,the developing effect does not increase with the content of diatrizoate increase.The developing effect of silver nanoparticle/calcium alginate microspheres increased with the of silver nanoparticles increased significantly in the experimental range,silver nanoparticle/calcium alginate microspheres is stable,at room temperature for one year later,silver nanoparticle/calcium alginate microspheres still have the development effect.Thirdly,prepare chitosan/calcium alginate microcapsule with one-step and two-step method by polyelectrolyte complexation technology,and using bovine serum albumin as model drug to prepare bovine serum albumin/calcium alginate/chitosan microcapsule,study the effect of preparation methods and chitosan molecular weight on the morphology,swelling behavior and drug release behavior of calcium alginate/chitosan microcapsule.The study found that chitosan/calcium alginate microcapsules prepared by two steps have good shape.Bovine serum albumin release rate in PBS and the swelling rate of chitosan/calcium alginate microcapsule prepared by one-step method were more than two-step preparation.Bovine serum albumin release rate in PBS and the swelling rate of chitosan/calcium alginate microcapsule prepared by low molecular weight chitosan are higher than high molecular weight chitosan preparation.Finally,using stepwise IPN method with glutaraldehyde as crosslinking agent and calcium chloride respectively,prepare calcium alginate/PVA IPN membranes and ciprofloxacin hydrochloride/calcium alginate/PVA IPN membranes with ciprofloxacin hydrochloride as the model drug.Discusses the content of sodium alginate and polyvinyl alcohol on the morphology,the water absorption rate,water retention rate,swelling ratio,permeability,mechanical properties and drug release behavior of the membranes.The results show that:the IPN membrane has smooth surface,a strong interaction between calcium alginate and PVA,drug has good compatibility with calcium alginate and PVA.Surface contact angle and permeability of IPN membrane ranged between calcium alginate membranes and cross-linked polyvinyl alcohol membrane.IPN membrane materials have salt sensitivity,the swelling properties of IPN membrane is better than that of calcium alginate membrane,the water absorption and water retention rate of calcium alginate/polyvinyl alcohol IPN membrane increase with increase of PVA content.With the PVA content increasing,the tensile strength of calcium alginate/polyvinyl alcohol IPN membrane is smaller and the elongation at break increase.Synergistic effect mechanism of drug release from pure calcium alginate film belongs to the Fick diffusion and bulk erosion,but mechanism of drug release from ciprofloxacin hydrochloride/calcium alginate/PVA IPN film belongs to the Fick diffusion,adding polyvinyl alcohol,slowing the calcium alginate matrix erosion,calcium alginate and PVA IPN membrane as the carrier of some drugs can control the drug release rate.Calcium alginate/polyvinyl alcohol IPN membrane has the role of controlling drug release and the release mechanism is Fick diffusion.
Keywords/Search Tags:calcium alginate, embolic microsphere, develop, drug release, microcapsule
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