جستجوی مقالات مرتبط با کلیدواژه "رهایش کنترل شده" در نشریات گروه "پزشکی"

In the present study, a biocompatible drug delivery system was prepared by using chitosan-gelatin nanofibers based on electrospinning method.

The nanofibers were prepared by electrospinning and cross-linked by glutaraldehyde to stabilize in aqueous medium. The surface morphology and approximate size of nanofibers were investigated by the scanning electron microscopy and optical microscope.

The nanofibers were characterized and the interaction types of drug-nanofiber matrix were evaluated by using FT-IR spectrum. The swelling of nanofibers was about 3.88% and the stability of nanofibers about 3 days was estimated.

The drug release experiment in phosphate buffer (PBS pH=7.4) showed that quick release occurred in early hours and then release rate was decrease and controlled release was continued for three more days. The results showed that the triamcinolone drug delivery system was well implemented and could be used as a functional patch in the future.

Pseudomonas aeruginosa is one of the most important causes of nosocomial infections. This study was planned to produce a new antimicrobial complex (ceftazidime loaded EDTA) and assess its release kinetic and antimicrobial effects on P. aeruginosa.
The loading of ceftazidime on EDTA was performed and confirmed by FT-IR spectroscopy. The evaluation of drug release was performed by using dialyze method at 0.5, 1, 2, 3, 4, 6, 8, 12, 24, 48, 72 and 96 h after ceftazidime loading on EDTA. The antimicrobial effect of the new drug on P. aeruginosa was investigated by macrodilution and well diffusion methods.
FT-IR spectroscopy demonstrated ceftazidime loading on EDTA about 26.01 mol%. Evaluation of ceftazidime release indicated a gradual rise in drug release up to 8 h reaching 96% after 72 h. Well diffusion assay demonstrated an enhanced antimicrobial effect of ceftazidime after loading on EDTA in comparison with ceftazidime alone. MIC and MBC of ceftazidime alone determined 2 and 4 µg/ml, respectively. MIC of the new antimicrobial complex was 0.5 µg/ml and its MBC was 1 µg/ml signifying the enhancement effect of EDTA on antibacterial activity of ceftazidime.
Our results showed that EDTA is potentially advantageous in controlling the release of ceftazidime as well as enhancing its antimicrobial effect against P. aeruginosa.

The aim of this research was to develop a new drug release systems based on Nanoparticles. In this study, the natural polymer chitosan was used for preparation of nanoparticles due to its unique properties, such as biocompatibility and biodegradability. The polymeric nano-drug controlled release system has been designed with experimental design D-optimal response surface methodology, for varied variables such as the concentration of acyclovir, concentration ratio of chitosan/ TPP and pH using the ionic gelation method. The nanoparticles were characterized morphologically by scanning electron microcopy (SEM), particle size analyser (DLS) for determining size, zeta and PdI, Fourier Transform Infra-Red (FTIR) Spectroscopy for determination of structure of nanoparticlesand thermo gravimetric analysis (TGA)for studying thermal behavior. The optimized nanoparticles were characterized. The size of the particles was detected to be 132±24.3 nm; zeta potential was 32±2.87 mV; PdI of particles was 0.159±0.05; and calculated EE% was 85±4.38%. An in-vitro release study of the prepared nanoparticles illustrated that the percentage of acyclovir released from the nanoparticles was 80.17±2.45% within 48 hrs. The optimized nanoparticles according to SEM image, exhibited segregated and non-aggregated nanoparticles with sub-spherical smooth morphology and also the high thermal stability of acyclovir nanoparticles at temperature up to 200°C due to TGA analysis, which indicated a well-established structure of nanoparticles.

Poly lactic co- glycolic acid (PLGA) and poly caprolacton (PCL) are highly applicable polymers in the field of drug delivery and tissue engineering scaffolds. Therefore, this study aimed to design an insulin-loaded PCL/PLGA hybrid nanofiber scaffold in order to be applied in attachment and growth of chondrocytes. Moreover, it can provide a vehicle for the controlled release of active insulin in a certain time period. Chondrocyte cells were isolated from septum cartilage tissue utilizing collagenase and were also cultured in monolayer, then the third-passage cells were seeded on the scaffolds. Insulin release from the PCL/PLGA hybrid nanofiber scaffold was examined by Radio Immuno Metric Assay (RIMA) during 22 days. Adherence, distribution and morphology of cells were observed by H&E and alcian blue staining. PCL/PLGA hybrid nanofiber scaffold revealed a slow and sustain release of insulin within three weeks. Chondrocytes were distributed evenly throughout the scaffolds. In addition, they sank into the pores of scaffold and maintained their rounded morphology. Biological activity of insulin has been maintained during 22 days of controlled release from hybrid nanofiber PCL/PLGA scaffold. Chondrocytes were distributed evenly throughout the scaffold and revealed a rounded morphology. Therefore, this scaffold provides a suitable carrier for chondrocyte growth as well as formation of tissue engineered cartilage.