A high-performance silicon micropump for an implantable drug delivery system

Author(s):  
D. Maillefer ◽  
H. van Lintel ◽  
G. Rey-Mermet ◽  
R. Hirschi
2020 ◽  
Vol 10 (7) ◽  
pp. 2595 ◽  
Author(s):  
Chih-Ling Huang ◽  
Wei Fang ◽  
Bo-Rui Huang ◽  
Yan-Hsiung Wang ◽  
Guo-Chung Dong ◽  
...  

Bioactive glass (BG) was made by the sol–gel method and doped with boron (B) to increase its bioactivity. Microstructures of BG and B-doped BG were observed by scanning electron microscopy, and phase identification was performed using an X-ray diffraction diffractometer. The ion concentrations released after soaking in simulated body fluid (SBF) for 1, 4, and 7 days were measured by inductively coupled plasma mass spectrometry, and the pH value of the SBF was measured after soaking samples to determine the variation in the environment. Brunauer–Emmett–Teller (BET) analysis was performed to further verify the characteristics of mesoporous structures. High performance liquid chromatography was used to evaluate the drug delivery ability of teicoplanin. Results demonstrated that B-doped BG performed significantly better than BG in parameters assessed by the BET analysis. B-doped BG has nanopores and more rough structures, which is advantageous for drug delivery as there are more porous structures available for drug adsorption. Moreover, B-doped BG was shown to be effective for keeping pH values stable and releasing B ions during soaking in SBF. The cumulative release of teicoplanin from BG and B-doped BG reached 20.09% and 3.17% on the first day, respectively. The drug release gradually slowed, reaching 29.43% and 4.83% after 7 days, respectively. The results demonstrate that the proposed bioactive glass has potential as a drug delivery system.


RSC Advances ◽  
2020 ◽  
Vol 10 (72) ◽  
pp. 44533-44544
Author(s):  
Ahmad Haghi ◽  
Heidar Raissi ◽  
Hassan Hashemzadeh ◽  
Farzaneh Farzad

Adsorption free energy of a molecule depends on where and how the molecule meets ZIF-8 surface.


2021 ◽  
Vol 71 (4) ◽  
pp. 679-687
Author(s):  
Jinglong Wang ◽  
Liqun Fan ◽  
Lihua Zhang ◽  
Dandan Zheng ◽  
Yingzi Wang ◽  
...  

Abstract To evaluate the bioavailability of ellagic acid loaded super-saturatable self-microemulsifying drug delivery system (S-SMEDDS), its pharmacokinetic properties were studied in rats with an ultra-high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry. The plasma samples were treated by solid-phase extraction method, and gallic acid was used as the internal standard when determining the concentration of ellagic acid. Results showed that the established analytical method was sensitive and accurate, which is applicable to the pharmacokinetic study of ellagic acid. The drug was found to be absorbed rapidly in vivo, and the plasma concentration-time curve showed double peaks, indicating that ellagic acid were reabsorbed by entero-hepatic circulation after oral administration. Compared with ellagic acid suspension, the apparent clearance of ellagic acid-loaded S-SMEDDS and SMEDDS reduced significantly, and the AUC 0~t of them were 4.7 and 5.8-fold increase, respectively. Therefore, the bioavailability of ellagic acid-loaded S-SMEDDS was higher than that of the suspension and SMEDDS.


Drug Research ◽  
2017 ◽  
Vol 67 (10) ◽  
pp. 564-575 ◽  
Author(s):  
Niyaz Ahmad ◽  
Rizwan Ahmad ◽  
Atta Naqvi ◽  
Md Alam ◽  
Rehan Abdur Rub ◽  
...  

Abstract Background Quercetin (Qur) and its major in vivo bioactive metabolites i. e., 3′-O-methyl quercetin, 4′-O-methyl quercetin and quercetin 7-O-β-D-glucuronide, may be used to treat cerebral ischemia however the poor aqueous solubility and less intestinal absorption of Qur results low bioavailability. Purpose To improve Qur bioavailability through preparation of nanoformulation and to develop and validate a sensitive quantification method for Qur detection in brain homogenate. Methods Qur-containing self-nanoemulsifying drug delivery system (Qur-SNEDDS) was developed to form oil-in-water nanoemulsions in situ. Ultra-high performance liquid chromatography electrospray ionization-synapt mass spectrometric method (UHPLC/ESI-QTOF-MS/MS) was developed and validated for quantification whereas for optimal recovery of analyte, a liquid-liquid extraction method (LLE) was used. Results A droplet size of 94.63±3.17 nm and zeta potential of −17.91±1.02 mV for nanoemuslion, elution time for Qur and internal standard (IS) Rutin as 1.21 and 1.50 min alongwith a transition at m/z 301.04/151.03 and 609.21/299.21, were observed respectively. Similarly, linear dynamic range (1.00 ng/mL–2 000.0 ng/mL), intra and inter-assay i. e., %CV of 0.26–2.04, lower limit of detection (LOD) 0.08 ng/mL as well as lower limit of quantitation (LOQ) as 0.131 ng/mL were also observed. Conclusion The developed method have advantage over previous all methods i. e., less time consuming (<3.0), low consumption of solvents (flow rate 0.20 mL/min.) via small size column, more accuracy and specificity as well as use of acetonitrile as compared to hazardous solvents. This certainly adds advantages for green chromatography technique and supports application of current developed method for quantification and evaluation of Qur-SNEDDS.


2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Shuguo Sun ◽  
Beiping Li ◽  
Tao Yang ◽  
Meihu Ma ◽  
Qinlu Lin ◽  
...  

Therapeutic efficacy and the regulation of drug release can be improved by using selective targeting drug delivery systems. In this paper, we have demonstrated avidin-immobilized magnetic nanoparticles (AMNPs) as a novel targeted drug delivery system to deliver iminobiotinylated daunomycin (IDAU). TEM, XRD, VSM, and FTIR were employed for the physicochemical characterization of the drug-loaded MNPs. The binding of IDAU had little effect on sizes of AMNPs (~35 nm), but the stability and dispersibility of the nanoparticles were improved. The study also found that the loading capacity and efficiency of nanoparticles were mainly dependent on affinity interaction between IDAU and AMNPs. The optimal loading capacity and efficiency of MNPs for IDAU were 0.408 ± 0.012 mg/g and 94.18 ± 2.64% according to the reversed-phase high-performance liquid chromatography (RP-HPLC) data, respectively. Under the conditions of pH 6.8 and 1 mmol/L of biotin, the drug-loaded MNPs released rapidly at beginning and then maintained at a certain controllable release level. The effect of IDAU on DLKP proliferation was tested, and the results showed that IC50 was (1.60 ± 0.05) × 10−3 mg/mL. Our findings indicated that AMNPs hold tremendous potential as an effective drug delivery system.


NANO ◽  
2021 ◽  
Vol 16 (03) ◽  
pp. 2150035
Author(s):  
Wenlong Li ◽  
Weiwei Zhang ◽  
Weihao Jin ◽  
Longbao Zhu ◽  
Wanzhen Li ◽  
...  

Design of high-performance drug delivery system is necessary to improve the anticancer ability of 5-fluorouracil (5-FU). In this work, we developed a pH-responsive 5-FU loaded and sodium alginate (SA) modified mesoporous silica nanoparticles (MSNs) drug delivery system (5-FU@MSN-SA). After 5-FU was loaded into the pores, MSNs were successfully functionalized with amino groups and then capped by sodium alginate. Compared to acidic conditions, the drug release rate in the neutral environment was quite low. Moreover, detailed investigations confirmed that 5-FU@MSN-SA can easily be up-taken by cancer cells and proved the high cytotoxicity to 4T1 cells. The calculated IC[Formula: see text] values for 5-FU and 5-FU@MSN-SA were 34.67[Formula: see text][Formula: see text][Formula: see text]g/mL and 54.95[Formula: see text][Formula: see text][Formula: see text]g/mL, respectively. These results indicated that 5-FU@MSNs-SA can be a promising nanoplatform in cancer therapy.


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