Preparation Of Intelligent Type Controlled Release Systems Based On Titanium Dioxide Nanotube Arrays And Their Release Behaviors

In order to satisfy the requirements about clinical applications of bone implant materials,investigators pay more attention to functional modification,advance of drug loading and controlled release of drugs.As a kind of the most interesting drug delivery systems(DDS)applied in bone implant materials,TNTs reflect absolute advantages,such as,drug loading,slow release and mechanical properties etc,which make TNTs be an excellent bone implant medical material.The outstanding properties of TNTs lay the profound foundation for TNTs as a sort of promising DDS.TNTs have been extensively explored as DDS for orthopedic surgery by anodic oxidation method,which is the most commonly used method.TNTs exist various advantages,including of controllable morphology,controllable size,uniform distribution,highly ordered,based on characters above,three smart drug delivery systems established in this paper for carrying the points to meet the needs of patients under different situations,meanwhile,the effect of preventing inflammation,eliminating inflammation in time to avoid pathological changes and promote bone growth can be achieved by founding different intelligent controlled release systems.Alendronate sodium was used as the growth promoter and ibuprofen and diclofenac sodium as anti-inflammatory agents.Self-triggered drug release system(SDDS),whose trigger switch is temperature,base material is TD,mixed with IBU at 50℃ to get mixture,and then,loaded into TNTs to prepare SDDS.In the preparation of near-infrared-light controlled drug delivery system(NDDS)whose trigger switch is NIR,TNTs modified by hydroxylation and amination following by loading GNPs and mixture into TNTs,we get NDDS.For the dual functional drug delivery system(DDDS),trigger switch is pH,the preparation process contains three steps,first,rubber head-type TNTs(R-TNTs)synthetized via secondary anodizing method,then,a large amount of alendronate sodium(ALN)loaded into R-TNTs under the action of an electric field,finally,carried diclofenac sodium/chitosan composite coating on the R-TNTs,DDDS prepared successfully,which release ALN when there’s no inflammation at the site,conversely,mass release of diclofenac sodium from the coating to eliminate the inflammation of the wound.A series of intelligent controlled-release systems established in this paper can meet the needs of patients in different situations,and have high practicability,applicability and good emergency response.More importantly,the method of loading drugs by electric field also provides a means for loading or immobilization of specific substances on a specific carrier.