Anti-Mucin1 aptamer-conjugated chitosan nanoparticles for targeted co-delivery of docetaxel and IGF-1R siRNA to SKBR3 metastatic breast cancer cells

Background: Targeted co-delivery of siRNA and a chemotherapeutic drug is an attractive approach to cancer drug design and treatment. This study was carried out to design an anti-Mucin1 aptamer [Apt]-conjugated chitosan nanoparticle [NP] for targeted co-delivery of insulin-like growth factor receptor 1 [IGF-1R] Silencer siRNA and docetaxel [DTX] to SKBR3 cells

Methods: Characterization of nano-drugs, cellular uptake of NPs, cell viability, and gene expression studies were evaluated based on metastatic breast cancer cells

Results:The results of this study showed that NPs had spherical and smooth morphology with 110-118 nm in size and had positive zeta potential [12-14 mV]. siRNA and DTX were considerably loaded into NPs. The appropriate conjugation of the Apt to the NPs was affirmed by gel electrophoresis. The Apt-conjugated NPs were observed to enhance the cellular uptake of NPs into the SKBR3 cells. Although the combination treatment significantly decreased the cell viability of SKBR3 cells, the augmentative effect was observed when Apt was conjugated to NPs. Furthermore, Apt-conjugated NPs dramatically reduced the genetic expression of IGF-1R, signal transducers and activators of transcription 3 [STAT3], matrix metalloproteinases [MMP9], and vascular growth factor [VEGF]

Conclusion: The targeted NPs may augment the targeting of pathways involved in tumorigenesis and metastasis of breast cancer. Therefore, more animal model experiments are needed to further clarify the efficacy and safety of this functionalized nanodrug

Preparation and antibacterial activity evaluation of 18-beta-glycyrrhetinic acid loaded PLGA nanoparticles

The aim of the present study was to formulate poly [lactide-co-glycolide] [PLGA] nanoparticles loaded with 18-beta-glycyrrhetinic acid [GLA] with appropriate physicochemical properties and antimicrobial activity. GLA loaded PLGA nanoparticles were prepared with different drug to polymer ratios, acetone contents and sonication times and the antibacterial activity of the developed nanoparticles was examined against different gram-negative and gram-positive bacteria. The antibacterial effect was studied using serial dilution technique to determine the minimum inhibitory concentration of nanoparticles. Results demonstrated that physicochemical properties of nanoparticles were affected by the above mentioned parameters where nanoscale size particles ranging from 175 to 212 nm were achieved. The highest encapsulation efficiency [53.2 +/- 2.4%] was obtained when the ratio of drug to polymer was 1:4. Zeta potential of the developed nanoparticles was fairly negative [-11 +/- 1.5]. In-vitro release profile of nanoparticles showed two phases: an initial phase of burst release for 10 h followed by a slow release pattern up to the end. The antimicrobial results revealed that the nanoparticles were more effective than pure GLA against P. aeuroginosa, S. aureus and S. epidermidis. This improvement in antibacterial activity of GLA loaded nanoparticles when compared to pure GLA may be related to higher nanoparticles penetration into infected cells and a higher amount of GLA delivery in its site of action. Herein, it was shown that GLA loaded PLGA nanoparticles displayed appropriate physicochemical properties as well as an improved antimicrobial effect

Docetaxel loaded PEG-PLGA nanoparticles: optimized drug loading, in vitro cytotoxicity and in vivo antitumor effect

In this study a 3-factor, 3-level Box-Behnken design was used to prepare optimized docetaxel [DTX] loaded pegylated poly lactide-co-glycolide [PEG-PLGA] NPs with polymer concentration [X1], drug concentration [X2] and ratio of the organic to aqueous solvent [X3] as the independent variables and particle size [Y1], poly dispersity index [PDI] [Y2] and drug loading [Y3] as the responses. The cytotoxicity of optimized DTX loaded PEG-PLGA NPs was studied in SKOV3 tumor cell lines by standard MTT assay. The in vivo antitumor efficacy of DTX loaded PLGA-PEG NPs was assessed in tumor bearing female BALB/c mice. The optimum level of Y1, Y2 and Y3 predicted by the model were 188 nm, 0.16 and 9% respectively with perfect agreement with the experimental data. The in vitro release profile of optimum formulation showed a burst release of approximately 20% [w/w] followed by a sustained release profile of the loaded drug over 288 h. The DTX loaded optimized nanoparticles showed a greater cytotoxicity against SKOV3 cancer cells than free DTX. Enhanced tumor-suppression effects were achieved with DTX-loaded PEG-PLGA NPs. These results demonstrated that optimized NPs could be a potentially useful delivery system for DTX as an anticancer agent

[ rapid method for extraction of water soluble beta[1,3] glucan from the cell wall of candida albicans]

In recent decades, beta-glucans have been used as important complementary and alternative medicines for numerous immunocompromised individuals and those with advanced cancer. The most active form of beta-glucans is beta[1,3]D-glucan and its most common source is cell wall of Candida albicans. Recently it has been introduced as a nano particle design to be used as a carrier for drug delivery. The current study researches a rapid method for the extraction of beta[1,3]D-glucans. The present study was conducted at Tarbiat Modares Medical University in 2012. Candida solubilized beta-glucans were obtained by oxidation of the cell wall with sodium hypochlorite and sodium hydroxide. The particle part could be solubilized by treatment with dimethylsulfoxide [DMSO] and zymolyase digestion to extract beta[1,3]Dglucan. The soluble fractions were lyophilized. We performed the Callose test to verify the presence of beta[1,3]D-glucans. Solubilized fractions were dissolved in D2O and 1HNMR spectra were measured. The soluble beta[1,3]D-glucan fraction which was derived from 1 g of dried Candida albicans germ tube weighed 190 mg. beta[1,3]D-glucan was verified by the Callose test and [1]H-NMR test compared with Curdlan [standard]. [1]H-NMR spectra verified the existence of beta[1,3]D-glucan in the final product. In the present study, extraction of beta[1,3]D-glucan by oxidation of the cell wall using sodium hypochlorite yielded more pure beta[1,3]D-glucans in comparison with other extraction methods. Thus it might represent a rapid method of extraction.

PEGylation of octreotide using an alpha,beta-unsaturated-beta-mono-sulfone functionalized Peg reagent

PEGylation is a well-established technique utilized to overcome the problems related to the therapeutic applications of pep tides and proteins. Reasons for the PEGylation of these biological macromolecules include reducing immunogenicity, proteolytic degradation and rapid clearance from blood circulation. Octreotide is an octapeptide analogue of naturally-occurred somatostatin. This peptide has elimination half-life of less than 2 h that requires frequent daily subcutaneous or intravenous administration. To address this issue, octreotide modification was investigated using bis-thiol alkylating PEG reagent. The required bisthiol alkylating reagent [V] was prepared from commercially available 4-acetyl benzoic acid in five steps. Octreotide disulfide bond was mildly reduced to liberate the two cysteine sulfur atoms followed by bis-alkylation to form PEGylated peptide. The PEG modification process was monitored through the reverse phase HPLC and 'H-NMR analysis. According to the HPLC chromatograms of PEGylation reaction, the peak with 30 min retention time was identified to be PEG-octreotide. In addition, H-NMR analysis showed a 7.44% degree of PEG substitution

Preparation of ethylcellulose coated gelatin microspheres as a multiparticulate colonic delivery system for 5-aminosalicilic acid

In the long-term management of ulcerative colitis patients, repeat dosing maybe required. Since 5-ASA is largely absorbed from the upper intestine, selective delivery of drugs into the colon may be regarded as a better method of drug delivery with fewer side effects and a higher efficacy. The aim of this study was to prepare and evaluate a double coated multiparticulate system for 5-ASA delivery using gelatin and ethylcellulose as the primary and secondary polymer respectively. Gelatin microspheres containing 5-aminosalicylic acid was produced using the solvent evaporation method. Prepared gelatin microspheres were spherical, free flowing, non-aggregated and showed no degradation in the acidic medium. Entrapment efficacy of microspheres was about 50%. Results showed that drug release was fast and complete and is affected by the amount of core material entrapped. Gelatin microspheres were then coated by ethylcellulose using a coacervation phase separation technique. The idea for this approach was to prepare a delayed drug delivery system, in which, ethylcellulose protects particles for the first 6 h transit through the gastrointestinal tract. However, it was shown that this system could provide a suitable drug release pattern for colonic delivery of active agents, as 30% of the drug was released from the ethylcellulose-coated microcapsules within 6 h, while this amount was 90% of the loaded drug for gelatin microspheres under the same condition

Ion-exchange, an approach to prepare an oral floating drug delivery system for diclofenac

Using ion-exchange resins, a multiple-unit type of oral floating dosage system has been prepared to prolong gastric emptying time of dosage form. The system is composed of beads of drug-resin complex, which are loaded with bicarbonate ions and coated with a hydrophobic polymer. The system is so designed that when the beads reach the stomach, chloride ions are exchanged with bicarbonate and drug ions. The generated CO[2] is entrapped in the polymeric coated resins and causes the beads to float. In this study, Amberlite-IRA 900 was loaded with diclofenac and bicarbonate ions, using a batch method. The beads were encapsulated with a hydrophobic polymer [ethyl cellulose or Eudragit RS-100]. To find an appropriate formulation, the factors affecting the drug loading, floating ability and drug release were investigated. Based on the result obtained, maximum loading efficiency was attained at 3 h, using an aqueous diclofenac solution and resin beads measuring 430 m in diameter. Drug release from both uncoated complexes of diclofenac-resin, and diclofenac-bicarbonate-resin occurred via particle-diffusion. The ethyl cellulose-coated beads have a desirable floating capability in comparison with the Eudragit RS-100 coated beads on HC1 0.1M solution containing 0.02% polysorbate 80

Effects of formulation variables on nifedipine microspheres prepared by solvent evaporation technique

Preparation and characterization of nifedipine microspheres using ethylcellulose as matrix polymer is described. Nifedipine microspheres were prepared by solvent evaporation technique. The influence of different parameters such as the effect of the concentration of internal and external phases, the amount of drug and the rate of stirring of the medium on the size distribution of microspheres were studied. The effect of drug/polymer ratio and mean particle size on the drug release pattern were also evaluated. Drug release from nifedipine microspheres was studied in a medium, which simulated the change in pH of the pathway of the microspheres from stomach to intestine. It was found that with increase in the concentration of the internal phase, the size of microspheres became larger. Increasing the amount of polyvinyl alcohol in the external phase reduced the size of microspheres. Dissolution was found to be inversely related to the pH, in a way that drug release decreased at higher pH: Drug release from microspheres with small mean particle size was faster than those with large mesh particle size and followed Higuchi model of kinetics