Formulation, characterization, and cellular toxicity assessment of tamoxifen-loaded silk fibroin nanoparticles in breast cancer.

Silk fibroin (SF) is a natural polymeric biomaterial that is widely adopted for the preparation of drug delivery systems. Herein, we aimed to fabricate and characterize SF nanoparticles loaded with the selective estrogen receptor modulator; tamoxifen citrate (TC-SF-NPs) and to assess their in vitro efficacy against breast cancer cell lines (MCF-7 and MDA-MB-231). TC-loaded SF-NPs were characterized for particle size, morphology, entrapment efficiency, and release profile. In addition, we examined the in vitro cytotoxicity of TC-SF-NPs against human breast cancer cell lines and evaluated the anticancer potential of TC-SF-NPs through apoptosis assay and cell cycle analysis. Drug-loaded SF-NPs showed an average particle size of 186.1 ± 5.9 nm and entrapment efficiency of 79.08%. Scanning electron microscopy (SEM) showed the nanoparticles had a spherical morphology with smooth surface. Tamoxifen release from SF-NPs exhibited a biphasic release profile with an initial burst release within the first 6 h and sustained release for 48 h. TC-SF-NPs exerted a dose-dependent cytotoxic effect against breast cancer cell lines. In addition, flow cytometry analysis revealed that cells accumulate in G0/G1 phase, with a concomitant reduction of S- and G2-M-phase cells upon treatment with TC-SF-NPs. Consequently, the potent anticancer activities of TC-SF-NPs against breast cancer cells were mainly attributed to the induction of apoptosis and cell cycle arrest. Our results indicate that SF nanoparticles may represent an attractive nontoxic nanocarrier for the delivery of anticancer drugs.

Parental perceptions, attitudes and acceptance of childhood immunization in Saudi Arabia: A cross sectional study.

OBJECTIVES: The widespread availability and use of vaccines have tremendously reduced morbidity, mortality and health care costs associated with infectious diseases. However, parental beliefs about vaccination are one of the major factors in achieving high vaccination rates. Thus, this study aims to assess the perceptions and attitudes regarding routine childhood immunization among Saudi parents. METHODS: A cross sectional study with a pre-tested 18-item questionnaire was conducted using 467 randomly selected parents from the Hail region of Saudi Arabia in the period between February 1st, 2016, and February 1st, 2017. The validated questionnaire consisted of three sections that collected information on participants' demographics, parents' awareness of vaccine benefits, and parents' practices regarding the immunization of their children. RESULTS: Female and male parents comprised 54.5% (255) and 45.5% (212) of the sample, respectively, and the response and completion rates were 97%. The majority of the respondents had received a formal education (94.1%, 439), were gainfully employed (62.9%, 294) and had a regular monthly income (73.3%). The majority of the respondents were aware of childhood vaccinations (78.9%), completed vaccinations mandated for children up to 5 years (86.2%), encouraged other parents to do so (89.9%), and had easy access to vaccines (90.5%). Sixty to ninety percent of the respondents were knowledgeable regarding the health benefits of vaccinations in children, even though 18.4% of their children had experienced vaccination-related minor adverse effects during or after vaccination of which 23.2% required doctor's visits. Health care professionals were the most frequent source of parents' vaccine-related information (65.2%), and vaccination reminder services provided by the Ministry of Health (MOH) via mobile phones were cited by 57.5% of respondents. CONCLUSIONS: Confidence in and acceptance of childhood vaccinations, perceptions of vaccine-related health benefits and ease of access to immunizations appeared to be quite good among Saudi parents.