SYNTHESIS AND CHARACTERIZATION OF HPMC/HAp/Fe3O4 COMPOSITE FOR HYPERTHERMIA APPLICATION

SYNTHESIS AND CHARACTERIZATION OF HPMC/HAp/Fe3O4 COMPOSITE FOR HYPERTHERMIA APPLICATION. Magnetic material become subject of intense research for hyperthermia application, and injectable magnetic hyperthermia for bone cancer is one of this research interest. In this study, composite of hydroxyapatite (HAp) and Fe3O4 in Hydroxypropyl-methyl cellulose (HPMC) matrix (HPMC/HAp/Fe3O4) has been synthesized in gel form that are expected can be applied for injectable bone substitute (IBS) in hyperthermia therapy. Composites were made using conventional methods by mixing HAp powder with ferrofluid Fe3O4 in HPMC solution. The composition of the composites were varied with the mass comparison of HPMC: HAp: Fe3O4 was 1: 0: 0; 1: 3: 0; 1: 2: 0.5; 1: 1: 0.25; and 1: 0: 3. The physical, chemical, and magnetic properties of the composites were characterized using X-Ray Diffractometer (XRD), Fourier Transform Infrared Spectrometry (FT-IR), Particle Size Analyzer (PSA), and Vibrating Sample Magnetometer (VSM). The XRD characterization results of the HPMC/HAp/Fe3O4 composite showed the crystalline phase of the constituent components. Saturation magnetization of the HPMC/HAp/Fe3O4 composite was 2.72 emu/g and 1.79 emu/g for the composition of 1: 2: 0.5 and 1:1:0.25 respectively. HPMC/HAp/Fe3O4 composite has superparamagnetic and biocompatible properties, so that can be applied as IBS in hyperthermia therapy for bone cancer

PENYERAPAN TIMBAL OLEH JERAMI TERMODIFIKASI SECARA SONIKASI

PENYERAPAN TIMBAL OLEH JERAMI TERMODIFIKASI SECARA SONIKASI.Telah dilakukan percobaan penyerapan logam berat Pb oleh jerami yang termodifikasi secara sonikasi. Modifikasi jerami secara sonikasi dilakukan dengan mengunakan alat ultrasonik jenis cleaning bath. Penyerapan logam berat Pb oleh jerami dilakukan secara catu dengan beberapa parameter, diantaranya pH larutan umpan (1, 2, 3, 4, 5, 6, dan 7), waktu kontak (5, 10, 15, 20, 25, dan 30 menit) , ukuran jerami (20, 40, 60, dan 80 mesh), perbandingan Pb terhadap jerami ( 0,25/0,5; 0,5/0,5; 0,75/0,5; dan 1,0/0,5 mg/g ). Penentuan struktur mikro jerami dilakukan dengan menggunakan alat Scanning Electron Microscope (SEM) dan analisis logam berat Pb dilakukan dengan mengunanan alat Spectrofotometer UV-VIS DMS 100. Dari hasil percobaan penyerapan logam berat Pb oleh jerami yang termodifikasi secara sonikasi dapat disimpulkan bahwa jerami yang dimodifikasi secara sonikasi layak dimanfaatkan sebagai bahan penyerap terhadap logam berat Pb. Dari percobaan diperoleh efisiensi penyerapan 94 % untuk larutan Pb 10 mg/L sebanyak 50 mL , pH larutan 5 dan waktu kontak 20 menit dan jumlah jerami 0,5 g. Bila dibandingan dengan modifikasi secara kimia, modifikasi secara sonikasi lebih menguntungkan karena jerami hasil sonikasi tidak mengalami kerusakan atau pembelahan serat, ikatan dengan logam Pb lebih kuat dan tidak memerlukan bahan kimia

CONTROLLED GROWTH OF IRON OXIDE MAGNETIC NANOPARTICLES VIA CO-PRECIPITATION METHOD AND NaNO3 ADDITION

Size controlled magnetic nanoparticle (MNPs) of iron oxide were prepared in the presence of NaNO3 via co-precipitation method followed by HNO3 peptizing according to Massart’s method. The MNPs size were reduced by addition of NaNO3 in varied molarity and at different stage of process. As an end product, stable water-base colloids were formed. XRD pattern analysis using Rietveld method confirmed Fe3O4/g-Fe2O3 phase formation with nanoscale crystallite size. This crystallite size significantly decrease with NaNO3 addition from 12 nm to smaller than 8 nm, and give end-result of decreasing magnetization as measured by VSM. Langevin fitting of magnetic hysteresis curve also revealed the magnetic core size of nearly the same behaviour. TEM results show bigger value for single magnetic nanoparticle of > 10 nm and < 10 nm for MNPs without and with NaNO 3 addition, respectively. However, PSA measurement still trace a low nanoparticle agglomeration of ~ 20 nm, even after surface peptization using HNO3. A possible mechanism is proposed to explain these characteristics formation especially of the MNP’s size

Development of Magnetic-Silica Particles and In-house Buffers Kit for SARS-CoV-2 and CDV RNA Extraction

Since the end of 2019, COVID-19 pandemic caused by the novel SARS-CoV-2 has become a serious problem for the world. Accurate and rapid techniques in testing and tracing are needed to control the virus spreading. Molecular diagnostics through gene amplification techniques, especially PCR, still become the gold standard for SARS-CoV-2 detection, which requires the first step of RNA extraction and purification. The limitations of commercial RNA extraction-purification kits during the pandemic caused a big problem in testing and tracing, especially for developing countries. A simple RNA extraction-purification kit based on magnetic-silica (MAGSi) beads and non-guanidine in-house buffers for RNA virus extraction-purification has been developed. Two types of MAGSi beads with different magnetic nanoparticles (MNPs) content were synthesized through a modified Stöber’s method using the sonication technique. The PCR result shows that both the MAGSi beads and the buffer can be used as a kit for RNA extraction-purification, tested for SARS-CoV-2 and Canine Distemper Virus. Further study shows that MAGSi-1 has better RNA extraction ability, and a higher concentration of RNA has been extracted. This is likely because of the smaller particle size distribution (50–1,500 nm distribution) and higher magnetization (20.2 emu/g) of MAGSi-1 compared to MAGSi-2 with 100–1,700 nm size distribution and 14.2 emu/g magnetization