Preparation and Characterization of Modified Polyethyleneimine Magnetic Nanoparticles for Cancer Drug Delivery

Magnetic nanoparticles with polymeric coating have great significance in drug delivery purpose. We intended to prepare a modified amphiphilic polymer with targeting susceptibility to reduce side effects to normal cells. In this study polyethyleneimine (PEI) as a polycationic polymer reacted with sebacoyl chloride to make a new amphiphilic polymer and folic acid as a targeting agent to reduce cytotoxicity of polymer and increase specific entrance of nanoparticles to cancerous cells. The obtained polymer (PEI-Sb-FA) was then coated on magnetic nanoparticles (MNPs) to stabilize them. The core-shell nanoparticles were characterized by different methods such as scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM). Curcumin was finally loaded on PEI-Sb-FA-MNPs and the release behavior was studied in different pH. Curcumin loading of 28.2% was obtained and released drug in acidic pH = 4.5 was more than pH = 7.4, showing drug release sensitivity toward pH of media

Mesoporous silica nanoparticles functionalized with folic acid/methionine for active targeted delivery of docetaxel

Abstract: Mesoporous silica nanoparticles (MSNs) are known as carriers with high loading capacity and large functionalizable surface area for target-directed delivery. In this study, a series of docetaxel-loaded folic acid- or methionine-functionalized mesoporous silica nanoparticles (DTX/MSN-FA or DTX/MSN-Met) with large pores and amine groups at inner pore surface properties were prepared. The results showed that the MSNs were successfully synthesized, having good pay load and pH-sensitive drug release kinetics. The cellular investigation on MCF-7 cells showed better performance of cytotoxicity and cell apoptosis and an increase in cellular uptake of targeted nanoparticles. In vivo fluorescent imaging on healthy BALB/c mice proved that bare MSN-NH2 are mostly accumulated in the liver but MSN-FA or MSN-Met are more concentrated in the kidney. Importantly, ex vivo fluorescent images of tumor-induced BALB/c mice organs revealed the ability of MSN-FA to reach the tumor tissues. In conclusion, DTX/MSNs exhibited a good anticancer activity and enhanced the possibility of targeted drug delivery for breast cancer

Application of Response Surface Method for Preparation, Optimization, and Characterization of Nicotinamide Loaded Solid Lipid Nanoparticles

Purpose: Solid lipid nanoparticles (SLNs) have been proven to possess pharmaceutical advantages. They have the ability to deliver hydrophilic drugs through lipid membranes of the body. However, the loading of such drugs into SLNs is challenging. Hydrophilic nicotinamide, a histone deacetylase inhibitor, is used to establish SLNs with enhanced encapsulation efficiency by using statistical design. Methods: The possible effective parameters of these particles’ characteristics were determined using pre-formulation studies and preliminary tests. Afterwards, the Response Surface Method (RSM) was utilized to optimize the preparation condition of SLNs. The effect of the amount of lipid, drug, surfactant, and the mixing apparatus were studied on particle size, zeta potential, and encapsulation efficiency of the obtained particles. The acquired particles were characterized in respect of their morphology, in vitro release profile, and cytotoxicity. Results: According to this study, all the dependant variables could be fitted into quadratic models. Particles of 107 nm with zeta potential of about -40.9 and encapsulation efficiency of about 36% were obtained under optimized preparation conditions; i.e. with stearic acid to phospholipon® 90G ratio of 7.5 and nicotinamide to sodium taurocholate ratio of 14.74 using probe sonication. The validation test confirmed the model’s suitability. The release profile demonstrated the controlled release profile following the initial burst release. Neither the nicotinamide nor the SLNs showed toxicity under the evaluated concentrations. Conclusion: The acquired results suggested the suitability of the model for designing the delivery system with a highly encapsulated water soluble drug for controlling its delivery

Preparation and evaluation of a thermosensitive liposomal hydrogel for sustained delivery of danofloxacin using mesoporous silica nanoparticles

BACKGROUND: Sustained release delivery system can reduce the dosage frequency and maintain the therapeutic level of drugs for a longer time. Biodegradable, biocompatible and thermosensitive chitosan-beta-glycerophosphate (C-GP) solutions can solidify at body temperature and maintain their physical integrity for a longer duration. OBJECTIVES: To develop a novel delivery system based on the integration of liposomes in hydrogel using mesoporous silica nanoparticles (MSNs) for sustained release of danofloxacin in farm animals. METHODS: The MSNs were prepared using N-cetyltrimethylammonium bromide and tetraethylortho silica. The liposomes were prepared by thin film hydration method. C-GP solution containing danofloxacin-loaded MSN liposomes underwent different in-vitro tests, including evaluation of the entrapment efficiency, gelation time, morphology, drug release pattern as well as antimicrobial activities against S. aureus and E. coli. RESULTS: The mean pore size of MSNs was 2.8 nm and the mean MSN entrapment efficiency was 45%. Kinetics of danofloxacin release from liposomal hydrogel followed the Higuchi’s model. This formulation was capable of sustaining the danofloxacin release for more than 96 h. The FTIR studies showed that there were no interactions between danofloxacin and hydrogel excipients. Scanning electron microscopy (SEM) showed that the formed gel had a continuous texture, while the swelled gel in the phosphate buffer had a porous structure. Microbiological tests revealed a high antibacterial activity for lipomosal hydrogel of danofloxacin-loaded MSN comparable with danofloxacin solution. CONCLUSIONS: The liposomal hydrogel solidified at body temperature, effectively sustained the release of danofloxacin and showed in vitro antibacterial effects

Preparation and in vitro evaluation of chitosan-based films for the sustained delivery of enrofloxacin

The implantable drug products are developed mainly to sustain the drug release. This study was conducted to formulate and evaluate cross-linked films of chitosan/β-glycerophosphate (β-GP) for the sustained delivery of enrofloxacin (ENR). Two types of formulations, single-layer (F1 and F2) and triple-layer (F3 and F4) films, were prepared. In vitro drug release, kinetic modelling, Fourier transform infrared spectroscopy (FTIR) spectra, morphological and microbiological studies were performed. Drug release from F1 and F2 continued up to 5 hours but from F3 and F4, it was extended over 96 and 168 hours, respectively. The cumulative drug release for F1, F2, F3 and F4 were 72.6, 70.1, 90.5 and 82.4%, respectively. The inhibition zones of bacterial growth by using positive controls and single layer films were significantly greater than those of triple-layer films (p < 0.05), indicating sustained drug release pattern of the multi-layer films.These findings suggest that the triple-layer chitosan/ β-GP films could be effective to deliver ENR for a long period

Pegembangan Model untuk Pembelajaran Keterampilan Menulis di Sekolah Dasar

Pembelajaran Bahasa Indonesia seringkali dianggap mudah oleh sebagian besar peserta didik, hal tersebut menjadikan tujuan pembelajaran dalam suatu kegiatan belajar mengajar tidak dapat dicapai secara optimal, salah satunya keterampilan menulis. Banyaknya model pembelajaran yang ditawarkan dalam dunia pendidikan nyatanya belum mampu mengatasi kekurangan tersebut. Tujuan dari penelitian ini adalah 1) untuk mengetahui pembelajaran keterampilan menulis di SD, 2) untuk mengetahui tingkat keterampilan menulis siswa, 3) untuk mengetahui kebutuhan terhadap model pembelajaran Bahasa Indonesia yang dapat meningkatkan keterampilan menulis siswa. Jenis penelitian yang dilakukan adalah penelitian kualitatif yang dilakukan melalui studi kasus dan studi literature. Subjek penelitiannya meliputi siswa kelas III Sekolah Dasar. Teknik pengumpulan data menggunakan triangulasi data/sumber yaitu data wawancara yang dilakukan dengan guru kelas III di sekolah yang berbeda dan triangulasi metode yaitu data wawancara, dan observasi. Analisis data dilakukan mulai dari pengumpulan data, reduksi data, penyajian data sampai verifikasi. Hasil penelitian pada studi pendahuluan ini adalah 1) kurikulum yang diterapkan di empat sekolah tersebut adalah Kurikulum Tingkat Satuan Pendidikan, 2) model pembelajaran yang digunakan guru sudah mengarah pada student center, 3) media yang digunakan berupa gambar yang sudah tertera pada buku, 4) penilaian dilakukan secara menyeluruh (mencakup empat keterampilan), 5)sebagian siswa belum mampu mencapai KKM. Kesimpulan dari studi pendahuluan ini adalah perlu dikembangkannya model pembelajaran Bahasa Indonesia yang dapat meningkatkan keterampilan menulis siswa

The Implicature in Flouting Maxim of Relation by the Main Character in Iron Man 2 Movie

Language takes an important role in human life. It is a tool for communication. People can get what they want and express their feelings by doing communication. In order to have good communication, the speaker and theThis study uses qualitative approach because the writer analyzes conversations in movie. The result of the study shows that there are 7 reasons why the main character flouts the maxim. This study also shows that there are 20 utterances containing flouting maxim of relation. Furthermore, this study alsoreveals that the using of flouting maxim of relation makes conversation moreinteresting.Hopefully, this study will inspire the next researchers to broaden their pointof view in order to look for the problems of the study. Furthermore, the writer alsosuggests the next researchers to look for other subject to be analyzed and use othertheories to analyze the data. Keywords: Cooperative principle, flouting maxim of relation, implicature, iron man 2 movie.hearer have to obey Cooperative Principle. However, there is a phenomenon when occasionally someone says one thing but he/ she means another. It usually happens with flouting maxim. One kind of flouting maxim is flouting maxim of relation. It occurs when a speaker or hearer responses which is very obviously irrelevant to the topic. The phenomenon is presented in the Iron Man 2 movie. This study aims to reveal the reasons why the main character flouts maxim of relation and what the impact to the conversation is

Conceptual model of the internationalization of medical education: Iranian faculty members’ perspective

Background and Objective: For about three decades, the internationalization concept has been crucial and necessary for medical education from the viewpoint of universities and the government. The "internationalization" definition depends on the educational conditions in related studies is not the same and indicated diverse concepts. Developing a conceptual model of medical faculties’ perspective is the first step to stimulating and localizing the internationalization program in Iran. Materials and Methods: A mixed-method was applied. Semi-structured interviews with experts were performed and an expert panel was formed by the snowball method. To complete the construction of the questionnaire, based on the experts' viewpoint, the internal consistency of the components was evaluated by Kendall's coefficient of concordance (W). The questionnaires were distributed randomly stratified selected 450 faculty members of medical universities and their responses were quantitatively analyzed using SPSS24 software. Cronbach's alpha index was applied to examine the reliability of the questionnaire-research tool. To identify the structural relationship between the components and dimensions, the method of Structural Equations with Partial Least Squares (PLS) was performed. Results: The developed conceptual model extracted and emphasis on two dimensions of at-home and cross-border. Conclusions: The model suggested that policymakers should consider internal and external internationalization dimensions and their seven rationales. Regardless of the higher significance of the external dimension, the hidden components of the internal dimension (in specific planning, and facilities/budget) demonstrated the highest impact factor on the internationalization of medical education. &nbsp

Synthesis and Characterization of Silk Fibroin- Coated Mesoporous Silica Nanoparticles for Tioguanine Targeting to Leukemia

Mesoporous silica nanoparticles (MSNs) are known as carriers with high loading capacity and large functionalizable surface area for target-directed delivery. In this work, large pore size MSNs were prepared by the co-condensation method. Tioguanine (TG) as a hydrophobic drug was loaded into the synthesized MSNs to prepare TG@MSNs. The results show MSNs were successfully synthesized and they have good loading efficiency and capacity for TG. Silk fibroin (SF) as an active targeting agent and pH-sensitive targeting release, is a natural protein from silkworm cocoons. It was used to coating MSNs to prepare SF/TG@MSNs. SF was Degummed and it was characterized by nuclear magnetic resonance (NMR), fourier transform infrared (FTIR) and field emission scanning electron microscopy (FESEM) methods. The MSNs were fully characterized by FESEM, transmission electron microscopy (TEM), zeta potential analysis, dynamic light scattering (DLS), nitrogen adsorption/desorption analysis, thermogravimetric analysis (TGA), X-ray diffraction (XRD) analysis, FTIR and UV-visible spectroscopies. The mechanism of TG release from SF/TG@MSNs were pH-sensitive. The in vitro release modeling revealed that TG released via the Higuchi model with fickian diffusion mechanism. In conclusion, SF/TG@MSNs exhibited a well synthesized and good payload for use in targeted drug delivery for leukemia

Hydrophilic solvents Correspondence to Author:

administration possesses many advantages including decreased or loss of first-pass drug metabolism, no gastro-intestinal degradation, long time delivery (especially for transdermal patches)