| Mesoporous silica nanoparticles(MSNs)have been widely used in the construction of stimulus-responsive drug carriers due to their unique and excellent properties.MSNs as substrate,AA and DMAEMA or CMCS and NIPAM as functional monomers,(NH4)2S2O8/Na HSO3 as initiators,MBA as crosslinking agent,MSNs@P(AA-coDMAEMA)and MSNs@CMCS-g-PNIPAM were prepared by free radical polymerization.DOX as model drug,the adsorption and sustained-release properties of the two drug carriers were studied.The best preparation conditions for MSNs@P(AA-co-DMAEMA)were 0.15 g of matrix,9.0 mmol of AA,2.4 mmol of DMAEMA,40 mg of initiator,and 20 mg of MBA;The best preparation conditions for MSNs@CMCS-g-PNIPAM were 0.15 g of matrix,0.40 g of CMCS,0.50 g of NIPAM,40 mg of initiator,and 50 mg of MBA.FT-IR,TG,SEM,TEM,XRD,XPS,and BET confirm that the polymer has been successfully coated on the surface of the mesoporous silica.The adsorption performance and mechanism results of the two drug carriers show that the two drug carriers have the best adsorption effect under p H 7.The equilibrium adsorption capacities of MSNs@P(AA-co-DMAEMA)and MSNs@CMCS-g-PNIPAM are 82.56 mg/g and 80.25 mg/g,drug loading rates are 7.63% and 7.43%,and the encapsulation rates are 80.98% and 82.99%.The adsorption process of the two drug carriers conforms to the Langmuir model and the pseudo-second-order kinetic model.The results of the sustained release performance of the two drug carriers show that the cumulative release rate of MSNs@P(AA-co-DMAEMA)-DOX under p H 5.5 reaches45.22%,which is 2.16 times that of p H 7.4,indicating that the drug carrier has obvious p H responsiveness;The cumulative release rate of MSNs@CMCS-g-PNIPAM-DOX under p H 5.5 and 45 ℃ reaches 87.30%,which is 4.63 times that of p H 7.4 and 37 ℃,indicating that the drug carrier has good p H and temperature dual responsiveness.The release process of the two drug carriers conforms to the Korsmeyer-Peppas model.Figure 48;Table 10;Reference 100... |
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