Development of Chitosan Nanoparticles as a Stable Drug Delivery System for Protein/siRNA

Chitosan nanoparticles (CS NPs) exhibit good physicochemical properties as drug delivery systems. The aim of this study is to determine the modulation of preparative parameters on the physical characteristics and colloidal stability of CS NPs. CS NPs were fabricated by ionic interaction with dextran sulphate (DS) prior to determination of their storage stability. The smallest CS NPs of 353 ± 23 nm with a surface charge of +56.2 ± 1.5 mV were produced when CS and DS were mixed at pH 4 and with a DS : CS mass ratio of 0.5 : 1. An entrapment efficiency of 98% was achieved when BSA/siRNA was loaded into the nanoparticles. The results also showed that particle size and surface charge of CS NPs were slightly changed up to 2 weeks when stored at 4 ∘ C. Greater particle size and surface charge were obtained with increasing the concentration of DS. In conclusion, NPs were sufficiently stable when kept at 4 ∘ C and able to carry and protect protein

Analysis of degree of errors in handwritten medication prescriptions in Rafha, Saudi Arabia

Purpose: To assess the prevalence of handwritten prescription errors in Rafha Central Hospital in Saudi Arabia, and to determine the most predominant type of prescription error. Methods: A cross-sectional study was carried out on randomly selected samples of hand-written prescriptions in out-patient and in-patient pharmacies of Rafha Central Hospital over a five-month period (October 2016 to February 2017). A data collection sheet specially designed for this purpose was used to collect relevant information. The collected prescriptions were analyzed for the presence of prescription errors based on prescription parameters defined by the World Health Organization (WHO) and current guidelines published in British National Formulary (BNF). Descriptive statistics and Microsoft Office were used for processing and analyzing the data collected. Results: Overall, 1019 prescription errors were identified. More than half of the total errors (610; 60 %) were associated with missing patient's information. Moreover, the parameters related to drug and prescriber information were absent in 204 (20 %) and 5 (0.4 %) prescriptions, respectively. In addition, 200 (19 %) miscellaneous errors related to date, legible handwriting and directions for patients were identified. Conclusion: This study discovered errors in hand-written prescriptions. A majority of the prescriptions did not adhere to accepted guidelines. The most common errors are absence of generic names of drugs, non-indication of duration of therapy or prescriber’s contact address, and absence of patient’s weight. Moreover, illegible handwriting was obvious in a substantial number of prescriptions

Penetration and Silencing Activity of VEGF Dicer Substrate siRNA Vectorized by Chitosan Nanoparticles in Monolayer Culture and a Solid Tumor Model In Vitro for Potential Application in Tumor Therapy

Penetration and distribution of drug through the avascular regions of human solid tumors after extravasation are crucial concerns for antitumor efficacy. To address this issue, an in vitro solid tumor model of multicellular layers (MCLs) of human colorectal cancer cells (DLD-1) was established. In an attempt to deliver Dicer substrate small interfering RNA (DsiRNA), chitosan (CS) nanoparticles have been developed for targeting vascular endothelial growth factor (VEGF) gene for tumor growth inhibition. The DsiRNA-CS nanoparticles prepared by ionic gelation method had provided maximal protection of DsiRNA in full human serum up to 48 h incubation. RT-PCR studies revealed significant concentration- and time-dependent knock-down of VEGF mRNA and its product due to uniform penetration of DsiRNA-CS nanoparticles throughout MCLs. Taken together, this study also demonstrated that DsiRNA-CS nanoparticles could effectively knock down VEGF gene as therapeutic target in monolayer culture or in solid tumor model for potential treatment of human colorectal carcinoma

Development of Chitosan Nanoparticles as a Stable Drug Delivery System for Protein/siRNA

Chitosan nanoparticles (CS NPs) exhibit good physicochemical properties as drug delivery systems. The aim of this study is to determine the modulation of preparative parameters on the physical characteristics and colloidal stability of CS NPs. CS NPs were fabricated by ionic interaction with dextran sulphate (DS) prior to determination of their storage stability. The smallest CS NPs of 353±23 nm with a surface charge of +56.2±1.5 mV were produced when CS and DS were mixed at pH 4 and with a DS : CS mass ratio of 0.5 : 1. An entrapment efficiency of 98% was achieved when BSA/siRNA was loaded into the nanoparticles. The results also showed that particle size and surface charge of CS NPs were slightly changed up to 2 weeks when stored at 4°C. Greater particle size and surface charge were obtained with increasing the concentration of DS. In conclusion, NPs were sufficiently stable when kept at 4°C and able to carry and protect protein

Stability, Intracellular Delivery, and Release of siRNA from Chitosan Nanoparticles Using Different Cross-Linkers.

Chitosan (CS) nanoparticles have been extensively studied for siRNA delivery; however, their stability and efficacy are highly dependent on the types of cross-linker used. To address this issue, three common cross-linkers; tripolyphosphate (TPP), dextran sulphate (DS) and poly-D-glutamic acid (PGA) were used to prepare siRNA loaded CS-TPP/DS/PGA nanoparticles by ionic gelation method. The resulting nanoparticles were compared with regard to their physicochemical properties including particle size, zeta potential, morphology, binding and encapsulation efficiencies. Among all the formulations prepared with different cross linkers, CS-TPP-siRNA had the smallest particle size (ranged from 127 ± 9.7 to 455 ± 12.9 nm) with zeta potential ranged from +25.1 ± 1.5 to +39.4 ± 0.5 mV, and high entrapment (>95%) and binding efficiencies. Similarly, CS-TPP nanoparticles showed better siRNA protection during storage at 4˚C and as determined by serum protection assay. TEM micrographs revealed the assorted morphology of CS-TPP-siRNA nanoparticles in contrast to irregular morphology displayed by CS-DS-siRNA and CS-PGA-siRNA nanoparticles. All siRNA loaded CS-TPP/DS/PGA nanoparticles showed initial burst release followed by sustained release of siRNA. Moreover, all the formulations showed low and concentration-dependent cytotoxicity with human colorectal cancer cells (DLD-1), in vitro. The cellular uptake studies with CS-TPP-siRNA nanoparticles showed successful delivery of siRNA within cytoplasm of DLD-1 cells. The results demonstrate that ionically cross-linked CS-TPP nanoparticles are biocompatible non-viral gene delivery system and generate a solid ground for further optimization studies, for example with regard to steric stabilization and targeting

Physicochemical Properties and In Vitro Cytotoxicity Studies of Chitosan as a Potential Carrier for Dicer-Substrate siRNA

Recently, Dicer-substrate small interfering RNA (DsiRNA) has gained attention owing to its greater potency over small interfering RNA (siRNA). However, the use of DsiRNA is restricted by its rapid degradation in vitro. To address this issue, chitosan nanoparticulate deliver yplatform for the Dicer-substrate siRNA (DsiRNA) was developed and characterized. Nanoparticles were prepared by simple complexation and ionic gelation methods. The mean particle size of DsiRNA-adsorbed chitosan nanospheres (DsiRNA-CS NPs) prepared by the ionic gelation method ranged from 225 to 335 nm, while simple complexation yielded DsiRNA-chitosan complexes (DsiRNA-CS complexes) ranging from 270 to 730 nm. The zeta potential of both types of nanoparticles ranged from +40 to +65 mV. TEM and AFM micrographs revealed spherical and irregular morphology of DsiRNA-CS NPs and DsiRNA-CS complexes. ATR-FTIR spectroscopy confirmed the presence of DsiRNA in the CS NPs/complexes. Both types of nanoparticles exhibited sustained release and high binding and encapsulation (100%) efficiency of DsiRNA. DsiRNA-CS NPs/complexes showed low, concentration-dependent cytotoxicity in vitro. DsiRNA-CS NPs showed better stability than the complexes when stored at 4 and 25°C. Thus, it is anticipated that CS NPs are promising vectors for DsiRNA delivery due to their stability, safety, and cost-effectiveness

Particle size, PDI, and zeta potential of unloaded CS-TPP/DS/PG Ananoparticles prepared at different CS concentrations, <i>n</i> = 3.

<p>Particle size, PDI, and zeta potential of unloaded CS-TPP/DS/PG Ananoparticles prepared at different CS concentrations, <i>n</i> = 3.</p

Protein adsorption ability of unloaded (a) and siRNA loaded CS-TPP/DS/PGA nanoparticles (0.1% w/v CS) in RPMI medium containing 10% FBS after 24 h (a) and 48 h (b) incubation, <i>n</i> = 3.

<p>Protein adsorption ability of unloaded (a) and siRNA loaded CS-TPP/DS/PGA nanoparticles (0.1% w/v CS) in RPMI medium containing 10% FBS after 24 h (a) and 48 h (b) incubation, <i>n</i> = 3.</p

Quantification of binding efficiency assay of siRNA loaded CS-TPP/DS/PGA nanoparticles.

<p>Mean percent of control is 80 ± 6 and relative density is 1.</p><p>* ND stands for no data as no bands detected</p><p>Quantification of binding efficiency assay of siRNA loaded CS-TPP/DS/PGA nanoparticles.</p

Cytotoxicity effect of siRNA-loaded CS-TPP/DS/PGA nanoparticles in DLD1 cells.

<p>After 24 h (a) and 48 h (b) incubation, <i>n</i> = 3.</p