Wahyu Ramadhan - Academia.edu (original) (raw)

Papers by Wahyu Ramadhan

EXPLORE, 2020

Lombok barat adalah salah satu kabupaten di Nusa Tenggara Barat yang bergerak dinamis dan terus m... more Lombok barat adalah salah satu kabupaten di Nusa Tenggara Barat yang bergerak dinamis dan terus maju, dengan banyak potensi yang perlu kita kembangkan untuk membangun wilayah Kabupaten Lombok Barat menjadi sebuah Kabupaten yang mampu bersaing dengan Kabupaten-Kabupaten lain di Indonesia. Layanan kesehatan seperti Rumah Patut Patuh Patju pun harus bersiap diri. Saat ini pasien yang telah merasakan penyakit, harus dipersulit dengan sistem pendaftaran pasien yang konvensional. Pasien adalah seseorang yang menerima pelayanan medik dari Rumah Sakit atau dokter, karena menderita suatu penyakit. Biasanya seorang pasien mempunyai tingkat kesabaran yang rendah. Untuk itu perlu ada terobosan dari rumah sakit atau pelayanan medik yang dapat memberikan kenyaman pasien dalam berobat. Dengan memiliki Sistem Pendaftaran Antrian Pasien Online pada suatu rumah sakit atau layanan medik, dalam pelayanan pada pasien akan teratur, sehingga menimbulkan kenyaman pada pasien. Karena fitur dari Sistem Penda...

Journal of Bioscience and Bioengineering, 2020

Liquid marbles (LMs) have recently shown a great promise as microbioreactors to construct self-su... more Liquid marbles (LMs) have recently shown a great promise as microbioreactors to construct self-supported aqueous compartments for chemical and biological reactions. However, the evaporation of the inner aqueous liquid core has limited their application, especially in studying cellular functions. Hydrogels are promising scaffolds that provide a spatial environment suitable for three-dimensional cell culture. Here, we describe the fabrication of redox-responsive hydrogel marbles (HMs) as a three-dimensional cell culture platform. The HMs are prepared by introducing an aqueous mixture of a tetra-thiolated polyethylene glycol (PEG) derivative, thiolated gelatin (Gela-SH), horseradish peroxidase, a small phenolic compound, and human hepatocellular carcinoma cells (HepG2) to the inner aqueous phase of LMs. Eventually, HepG2 cells are encapsulated in the HMs then immersed in culture media, where they proliferate and form cellular spheroids. Experimental results show that the Gela-SH concentration strongly influences the physicochemical and microstructure properties of the HMs. After 6 days in culture, the spheroids were recovered from the HMs by degrading the scaffold, and examination showed that they had reached up to about 180 mm in diameter depending on the Gela-SH concentration, compared with 60 mm in conventional HMs without Gela-SH. After long-term culture (over 12 days), the liver-specific functions (secretion of albumin and urea) and DNA contents of the spheroids cultured in the HMs were elevated compared with those cultured in LMs. These results suggest that the developed HMs can be useful in designing a variety of microbioreactors for tissue engineering applications.

Polymer Journal, 2020

Biofunctional hydrogels prepared by a peroxidase, especially horseradish peroxidase (HRP), serve ... more Biofunctional hydrogels prepared by a peroxidase, especially horseradish peroxidase (HRP), serve as an excellent class of materials or platform for the development of cellular scaffolds because their biocompatibility and mild and tunable reaction conditions provide them with desirable properties. In this focus review, we summarize our decade of research into HRPmediated fabrication of biofunctional hydrogels and their applications, in particular cell culture scaffolds. A brief overview of potential substrates employed in HRP and improvement of the HRP hydrogelation system from the initial step until the hydrogen peroxide removal stage in an effort to meet environmental standards is discussed. We highlight our system and describe its biocompatibility and ability to functionalize molecules to support biofabrication by increasing cellular adhesiveness, retaining growth factor affinity, and finally accelerating the formation of two-and three-dimensional multicellular architectures. In the last section, we outline the adoption of hydrogelation as a self-standing, compartmentalized reaction system, i.e., the use of hydrogel marble to conduct cell-free biosynthesis. We believe that this HRP-mediated hydrogel system offers great potential not only as a cell culture scaffold but also for various biomedical applications.

Scientific Reports, 2020

In this report, a strategy for constructing three-dimensional (3D) cellular architectures compris... more In this report, a strategy for constructing three-dimensional (3D) cellular architectures comprising viable cells is presented. The strategy uses a redox-responsive hydrogel that degrades under mild reductive conditions, and a confluent monolayer of cells (i.e., cell sheet) cultured on the hydrogel surface peels off and self-folds to wrap other cells. As a proof-of-concept, the self-folding of fibroblast cell sheet was triggered by immersion in aqueous cysteine, and this folding process was controlled by the cysteine concentration. Such folding enabled the wrapping of human hepatocellular carcinoma (HepG2) spheroids, human umbilical vein endothelial cells and collagen beads, and this process improved cell viability, the secretion of metabolites and the proliferation rate of the HepG2 cells when compared with a two-dimensional culture under the same conditions. A key concept of this study is the ability to interact with other neighbouring cells, providing a new, simple and fast metho...

ACS Applied Bio Materials, 2019

Biologically active artificial scaffolds for cell seeding are developed by mimicking extracellula... more Biologically active artificial scaffolds for cell seeding are developed by mimicking extracellular matrices using synthetic materials. Here, we propose a feasible approach employing biocatalysis to integrate natural components, that is, gelatin and heparin, into a synthetic scaffold, namely a polyethylene glycol (PEG)-based hydrogel. Initiation of horseradish peroxidasemediated redox reaction enabled both hydrogel formation of tetra-thiolated PEG via disulfide linkage and incorporation of chemically thiolated gelatin (Gela-SH) and heparin (Hepa-SH) into the polymeric network. We found that the compatibility of the type of gelatin with heparin was crucial for the hydrogelation process. Alkaline-treated gelatin exhibited superior performance over acid-treated gelatin to generate dual functionality in the resultant hydrogel originating from the two natural biopolymers. The Gela-SH/Hepa-SH dual functionalized PEG-based hydrogel supported both cellular attachment and binding of basic fibroblast growth factor (bFGF) under cell culture conditions, which increased the proliferation and phenotype transformation of NIH3T3 cells cultured on the hydrogel. Inclusion of bFGF and a commercial growth factor cocktail in hydrogel matrices effectively enhanced cell spreading and confluency of both NIH3T3 cells and HUVECs, respectively, suggesting a potential method to design artificial scaffolds containing active growth factors.

Jurnal Pengolahan Hasil Perikanan Indonesia, 2018

Abstrak Gracilaria sp. merupakan salah satu rumput laut penghasil agar yang sangat potensial. Pro... more Abstrak Gracilaria sp. merupakan salah satu rumput laut penghasil agar yang sangat potensial. Proses ekstraksi agar secara konvensional dilakukan pada suhu tinggi (80-100°C) serta waktu 2-3 jam, sehingga memerlukan energi yang tinggi. Salah satu metode alternatif untuk mengurangi energi ekstraksi adalah dengan bantuan gelombang ultrasonik (ultrasoniksi). Penelitian ini bertujuan menentukan pengaruh suhu dan waktu ultrasonikasi pada ekstraksi agar terhadap nilai rendemen dan karakteristik agar yang dihasilkan.. Agar diekstraksi dengan sonikasi pada suhu 50 atau 60°C, selama 45 atau 60 menit. Agar yang diperoleh diukur rendemen, viskositas dan derajat putihnya. Efisisensi energi dianalisis dengan menghitung rasio energi yang dibutuhkan terhadap jumlah agar yang dihasilkan.. Penggunaan ultrasonikasi berpengaruh nyata dalam meningkatkan rendemen, dan meningkatkan efisiensi penggunaan energi input yang digunakan. Karakteristik agar terpilih dengan perlakuan suhu esktraksi 60°C selama 60 menit memiliki rendemen 12,45%, viskositas 35,8 cP, derajat putih 50,96%, kadar air 12,59%, kadar abu 7,07%, kadar sulfat 3,67% dan kekuatan gel 108,03 g/cm 2. Agar yang yang dihasilkan termasuk native agar berkekuatan gel rendah. Kata kunci: energi rendah, rendemen tinggi, waktu singkat Extraction of native agar from Gracillaria sp with ultrasonic acceleration at low temperature

Jurnal Pengolahan Hasil Perikanan Indonesia, 2017

Tallying agar powder as a texturizer in guava single sheet jam instigate the product more conveni... more Tallying agar powder as a texturizer in guava single sheet jam instigate the product more convenience to consumed. The aims of this research were to determine the best concentration of sucrose, citric acid and agar powder to form a good quality guava jam slice. The research method are optimization and formulation<br />of sucrose, citric acid and agar-agar on making guava jam single sheets product. Physochemical and sensory tests were performed to reveal the best formulation of guava jam slice and the Bayes method used to determine the optimization of the selected formula. Based on the results of formulation and analysis, it<br />was obtained that the guava jam slice with Acidulant concentration (0.02%, 0.04%, 0.06%), sucrose (70%, 80%, 90%, 100%) and agar powder (0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%) had pH 3.63-3.90, sugar content 34.68 g/100 g – 35.76 g/100 g, color intensity L*, a*, b* with ΔE* value was 37,88-53,97, fiber content 1.01%-1.59%, and water activity 0.852-...

Jurnal Mahasiswa Teknologi Pendidikan, 2014

Pada mata pelajaran Biologi yang terdapat pada SMAN 1 GRATI Pasuruan pada materi Biotechnology kh... more Pada mata pelajaran Biologi yang terdapat pada SMAN 1 GRATI Pasuruan pada materi Biotechnology khususnya tentang proses pembuatan tempe, siswa belum bisa mempraktekkan dan melihat secara langsung tentang pembuatan tempe tersebut, dikarenakan keterbatasan tempat, waktu, dan sumber belajar (tempat produksi tempe) yang tidak memungkinkan untuk siswa dating ke pabrik tersebut. Dari hasil observasi yang didapat dari nilai ulangan harian pada mata pelajaran Biologi Proses pembuatan tempe nilai rata rata siswa masih belum mencapai KKM. Penjelasan mengenai proses tersebut hanya dijelaskan secara lisan dan menggunakan papan tulis, serta buku paket yang dikemas dalam power point sehingga pembelajaran yang terjadi didalam kelas bersifat konvensional yaitu textbook oriented dan teacher centered. Rumusan masalah dari penelitian ini yaitu diperlukan pengembangan media video pembelajaran mata pelajaran biologi tentang proses pembuatan tempe yang layak dan efektif untuk siswa kelas XII SMA Negeri 1 Grati Pasuruan. Metode penelitian ini adalah deskriptif kualitatif dan kuantitaf. Data dikumpulkan dengan menggunakan teknik analisis data yaitu wawancara, angket dan tes. Teknik analisis data dengan menggunakan wawancara dan tes digunakan untuk memperoleh data kualitatif tentang kelayakan media Video Pembelajaran yang digunakan untuk pembelajaran dikelas, sedangkan teknik analisis data dengan menggunakan tes digunakan untuk mengetahui apakah media Video Pembelajaran efektif digunakan dengan melalui soal uji pretest dan uji posttest. Berdasarkan hasil analis data ahli materi dan ahli media dapat ditarik kesimpulan sebagai berikut : (a) hasil presentase Ahli Materi I: 100% (baik sekali), (b) hasil presentase Ahli Materi II: 93,75 % (baik sekali), (c) hasil presentase Ahli Media I: 95,2% (baik sekali), (d) hasil presentase Ahli Media II: 90,47 % (baik sekali). Melalui hasil angket uji coba produk, dapat disimpulkan bahwa : (a) hasil presentase uji orang perorangan 93,3 % (baik sekali), (b) hasil presentase uji coba kelompok kecil 89 % (baik sekali), serta (c) hasil presentase pada uji coba kelompok besar 95,2 % (baik sekali). Dengan hasil yang diperoleh tersebut, dapat disimpulkan bahwa media Video Pembelajaran ini dikategorikan sangat baik dan layak digunakan. Berdasarkan hasil perhitungan dengan taraf signifikan 5%, db = N-1 (36-1)= 35, sehingga diperoleh ttabel 2,021. Jadi thitung lebih besar dari ttabel yaitu 5,575 > 2,021. dengan demikian perbedaan hasil pre-test dan post-test tersebut dinyatakan Efektif. Dengan demikian media Video Pembelajaran tersebut dinyatakan Layak dan Efektif. Kata kunci: Video Pembelajaran

Jurnal Teknologi dan Industri Pangan, 2014